Crown heights North Association

There are many great resources out there for those who own historic and/or landmarked buildings. Below is a partial list of information from the LPC  and the site is a wealth of information.
LPC Facts

http://www.nyc.gov/html/lpc/html/faqs/faqs.shtml 

The LPC RowHouse Manual     (large file)

LPC Work Guide

LPC Rowhouse Styles

LPC Rules

http://www.nyc.gov/html/lpc/html/forms/publications.shtml  

Historic District Council Landmarking Faqs
http://hdc.org/FAQ.pdf