NYC has so many public libraries --in three different systems!--and you may find what you want in one of them. Since they are by definition "public", anyone can visit there with no prior arrangements needed, and as an FIT student or employee, you can get a free library borrower's card for each system (New York Public Library for Bronx, Manhattan & Staten Island, Queens Library, and Brooklyn Public Library) even if you live in a different borough or outside of New York City.
As a current FIT student or employee, you have full access--no appointment or referral needed, and including borrowing privileges--to all other State University of New York (SUNY) libraries. (not to be confused with CUNY libraries which are part of a different university system)
If you still want or need to use another college's library, speak to one of the Research Services Librarians at FIT. Most NYC-area colleges have reciprocal arrangements, but there are restrictions. You'll need a referral card from FIT to get access (ask us about METRO referrals) and you usually can't borrow items-- just use them on premises. Some libraries also limit when you can visit and may limit any single user to a certain number of visits per semester.
If you have some time, you can request specific items that the FIT Library doesn't have through InterlIbrary Loan (ILL)
If you are not a current FIT or SUNY student or employee, you must request an appointment in order to use the FIT Library. Please see Visit the Libraryand submit your request through the form on that page.