The laws governing the legal use, storage and carrying of firearms are constantly changing. Below are the applicable laws in the State of New York as of 2/13/2013. The below information is designed to be a guide and not the final word. If you have specific questions, please refer to  the State of New York legislation at public.leginfo.state.ny.us.

Eligibility
No license shall be issued or renewed pursuant to this section   except   by   the  licensing  officer,  and  then  only  after investigation and finding that all statements in a proper application for a license are true.
No license shall be issued or renewed except for an applicant 
(a)  twenty-one years of age or older, provided, however, that where such applicant has been honorably discharged from the United States  army, navy, marine corps, air force or coast guard, or the national guard of the state of New York, no such age  restriction  shall apply 
(b)  Of good moral character.
(c) Who has not been convicted anywhere of a felony or a serious offense.
(d) Who has stated whether he or she has ever suffered any mental illness or been confined to any hospital or institution, public or private, for mental illness.
(e) who has not had a license revoked or  who  is  not  under  a  suspension  or ineligibility  order issued pursuant to the provisions of section 530.14 of the criminal procedure law or section eight  hundred  forty-two-a of the  family  court  act.
(f)  in  the  county  of  Westchester, who has successfully completed a firearms safety course and test as evidenced by a certificate of completion issued in his or her name and  endorsed  and affirmed under the penalties of perjury by a duly authorized instructor,  except  that:
1.  persons who are honorably discharged from the United  States army, navy, marine corps or coast guard, or of the national guard of the state of New York, and produce evidence of official qualification
  in firearms during  the  term  of  service  are  not  required  to  have completed those hours of a firearms safety course pertaining to the safe use,  carrying,  possession,  maintenance  and storage of a firearm; and
  2. Persons who were licensed to possess a pistol or revolver prior to the effective date of this paragraph are not required to have completed a firearms safety course and test.
(g) Concerning whom no good cause exists for the denial of the license.
No person shall engage in the business of gunsmith or dealer in firearms unless licensed pursuant to this section. An applicant to engage in such business shall also be a citizen of the United States, more than twenty-one years of age and maintain a place of business in the city or county where the license is issued.  For such business, if the applicant is a firm or partnership, each member there of shall comply with all of the requirements set forth in this subdivision.

Types of licenses
A license for gunsmith or dealer in firearms shall be issued to engage in such business. A license for a pistol or revolver, other than an assault weapon or a disguised gun, shall be issued to 
(a)  Have and possess in his dwelling by a householder.
(b) Have and possess in his place of business by a merchant or storekeeper.
(c)  Have and carry concealed while so employed by a messenger employed by a banking institution or express company. 
(d)  Have  and  carry concealed  by  a  justice  of  the  supreme court in the first or second judicial departments, or by a judge of the New York city civil court  or the  New York city criminal court.
(e) Have and carry concealed while so employed by a regular employee of an institution of the state, or of any county, city, town or  village,  under  control  of  a  commissioner  of correction  of  the city or any warden, superintendent or head keeper of any  state  prison,  penitentiary,  workhouse,  county  jail  or   other institution  for  the detention of persons convicted or accused of crime or held as witnesses in criminal cases,  provided  that  application  is  made  therefor  by  such  commissioner,  warden,  superintendent or head  keeper.
(f) Have and carry concealed, without regard  to  employment  or  place  of  possession,  by  any  person when proper cause exists for the  issuance thereof.
(g)  Have,  possess,  collect  and  carry  antique  pistols  which  are  defined  as  follows: 
(i)  any single shot, muzzle  loading pistol with a matchlock, flintlock, percussion cap,  or  similar  type  of  ignition  system  manufactured in or before l898, which is not  designed  for using rim fire or conventional center fire fixed ammunition;  and
(ii) Any replica of any pistol described in clause (I) here of if such replica--
(1)  is  not  designed or redesigned for using rimfire or conventional  centerfire fixed ammunition, or                                                                                                                                                                        (2) uses rimfire or conventional centerfire fixed ammunition which  is  no  longer  manufactured  in  the United States and which is not readily  available in the ordinary channels of commercial trade.

Applications
(a) Applications shall be made and  renewed,  in  the case  of  a  license  to  carry  or possess a pistol or revolver, to the licensing officer in the city or county, as the case may be,  where  the  applicant resides, is principally employed or has his principal place of  business  as  merchant  or storekeeper; and, in the case of a license as  gunsmith or dealer in firearms, to  the  licensing  officer  where  such  place  of  business  is located. Blank applications shall, except in the city of New York, be approved as to form by the superintendent of  state  police.  An  application  shall  state  the  full  name,  date of birth,  residence, present occupation of each person or individual  signing  the  same,  whether  or  not he is a citizen of the United States, whether or  not he complies with  each  requirement  for  eligibility  specified  in  subdivision  one of this section and such other facts as may be required  to show the good character, competency and integrity of each  person  or  individual  signing  the application. An application shall be signed and verified by the applicant. Each individual signing an application shall submit  one photograph of himself and a duplicate for each required copy  of the application. Such photographs shall have been taken within thirty days prior to filing the application. In case of a license  as  gunsmith  or  dealer  in  firearms,  the photographs submitted shall be two inches  square, and the application shall also state the previous occupation  of  each  individual  signing the same and the location of the place of such  business, or of the bureau, agency, sub-agency, office or  branch  office  for  which  the license is sought, specifying the name of the city, town  or village, indicating the street and number and otherwise  giving  such  apt description as to point out reasonably the location thereof. In such case,  if the applicant is a firm, partnership or corporation, its name,  date and place of formation, and principal place of  business  shall  be  stated.  For such firm or partnership, the application shall be signed and verified by each individual composing or intending to  compose  the  same, and for such corporation, by each officer thereof.
(b)   Application   for   an exemption under paragraph seven-b of subdivision a of section 265.20 of this chapter. Each applicant desiring  to obtain the exemption set forth in paragraph seven-b of subdivision  a  of  section 265.20 of this chapter shall make such request in writing of  the licensing officer with whom his application for a license is  filed,  at  the  time  of  filing such application. Such request shall include a  signed and verified statement by the person authorized to  instruct  and  supervise the applicant, that has met with the applicant and that he has  determined  that,  in his judgment, said applicant does not appear to be  or poses a threat to be, a danger to himself  or  to  others.  He shall include  a copy of his certificate as an instructor in small arms, if he  is required to be certified, and state his address and telephone number.  He shall specify the exact  location  by  name,  address  and  telephone  number  where  such  instruction will take place. Such licensing officer  shall, no later than ten business days after such  filing,  request  the  duly   constituted   police  authorities  of  the  locality  where  such  application is made to investigate and ascertain any  previous  criminal  record  of  the  applicant pursuant to subdivision four of this section.  Upon completion of this investigation, the police authority shall report  the  results  to  the  licensing  officer without unnecessary delay. The  licensing officer shall no  later  than  ten  business  days  after  the  receipt  of  such  investigation,  determine  if  the applicant has been  previously denied a  license,  been  convicted  of  a  felony,  or  been  convicted  of  a  serious  offense, and either approve or disapprove the  applicant for exemption purposes based upon such determinations. If  the  applicant  is  approved  for  the exemption, the licensing officer shall  notify the appropriate  duly  constituted  police  authorities  and  the  applicant.  Such  exemption  shall  terminate if the application for the  license is denied, or at any earlier time  based  upon  any  information  obtained  by the licensing officer or the appropriate police authorities  which  would  cause  the  license  to  be  denied.  The applicant   and appropriate   police   authorities   shall   be notified  of  any  such  terminations.

License/ revocation and suspension
The conviction of a licensee anywhere of a felony or serious offense shall operate as a revocation of the license.  A  license may be revoked or suspended as provided for insertion 530.14 of the criminal procedure law or  section  eight  hundred  forty-two-a  of  the  family  court  act.  Except  for  a license issued  pursuant to section 400.01 of this article, a license may be revoked and  cancelled at any time in the city of New York, and in  the  counties  of  Nassau  and Suffolk, by the licensing officer, and elsewhere than in the  city of New York by any judge or justice of a court of record; a license  issued pursuant to section 400.01 of this article  may  be  revoked  and  cancelled  at  any time by the licensing officer or any judge or justice  of a court of record. The official revoking a license shall give written notice thereof without unnecessary delay to the executive department, division of state police, Albany, and shall also notify immediately the duly constituted police authorities of the locality.

Fees
In the city of New York and the county of Nassau, the annual license fee shall be $25.00 for gunsmiths and $50.00 for dealers in firearms.  In such city, the city council and in the
county of Nassau the Board of  Supervisors  shall  fix  the  fee  to  be  charged  for  a  license  to  carry  or possess a pistol or revolver and  provide for the disposition of such fees. Elsewhere in  the  state,  the  licensing  officer  shall  collect  and pay into the county treasury the  following fees: for each  license  to  carry  or  possess  a  pistol  or  revolver,  not  less than $3.00 nor more than $10.00 as may  be determined by the legislative body of the county; for each  amendment  thereto,  $3.00, and $5.00 in the county of Suffolk; and  for each license issued  to  a  gunsmith  or  dealer  in  firearms,  $10.00.  The fee for a duplicate license shall be $5.00 dollars. The fee  for processing  a  license  transfer  between  counties  shall  be  five  dollars.  The  fee  for  processing  a  license or renewal thereof for a qualified  retired  police  officer   as   defined   under   subdivision  thirty-four  of  section  1.20  of  the  criminal  procedure  law,  or a  qualified retired sheriff, undersheriff, or deputy sheriff of  the  city  of  New  York  as  defined  under subdivision two of section 2.10 of the  criminal procedure  law,  or  a  qualified  retired  bridge  and  tunnel  officer,  sergeant  or  lieutenant  of  the tri-borough bridge and tunnel authority as defined under subdivision twenty of  section  2.10  of  the  criminal  procedure  law, or a qualified retired uniformed court officer  in the unified court system, or a qualified retired court clerk  in  the unified  court  system  in the first and second judicial departments, as  defined in paragraphs a and b of subdivision twenty-one of section  2.10  of the criminal procedure law or a retired correction officer as defined  in subdivision twenty-five of section 2.10 of the criminal procedure law  shall be waived in all counties throughout the state.

In New York City and Nassau County, the City Council and Board of Supervisors, respectively, set the license fees without regard to the state law limitation.

Weapons/Off limits                                                                                                                                                                                                                                                                                         
1. Firearms are NOT permitted in courthouses under the rules of the NYS Office of Court Administration, which have the force and effect of law.
2. Federal law bans firearms in federal courthouses and US attorney offices, except for law enforcement personnel on official business.
3. Certain cities and all counties may, under home rule options, ban firearms from their governmental buildings.
4. He knowingly has in his possession a rifle, shotgun or firearm in or upon a building or grounds, used for educational purposes, of any school, college or university, except the forestry lands, wherever located, owned and maintained by the State University of New York college of environmental science and  forestry, without the written authorization of such educational institution.
5. At any facility of the New York Department of Mental Hygiene, or any residential facility that has an operating certificate issued by the Department.
6. At any facility operated or licensed by the Office of Mental Health of the Department of Mental.