Below are some links put together to hopefully assist you.

NYC Department of Finance:http://www.nyc.gov/html/dof/html/home/home.shtml

On line NYC Register: http://a836-acris.nyc.gov/Scripts/Coverpage.dll/index

NYC Rent Guidelines Board: http://www.housingnyc.com/

NYS Division of Housing and Community Renewal: http://www.dhcr.state.ny.us/

Rent Stabilization Association: http://www.rsanyc.org/

Real Estate Board of New York: http://www.rebny.com/

NYC Dept. of Buildings: http://www.nyc.gov/html/dob/html/home/home.shtml

NYC Dept. of Housing Preservation & Development: http://www.nyc.gov/html/hpd/html/home/home.shtml

Landmarks Preservation Commission: http://www.nyc.gov/html/hpd/html/home/home.shtml

The New York Landmarks Conservacy: http://www.nylandmarks.org/

NYC Real Property Income & Expense Forms: http://www.nyc.gov/html/dof/html/pub/pub_property_rpie.shtml

Click on the category you are interested in: