Many genealogists, having tracked down information about their family members and ancestors, are beginning to investigate the buildings where those people once lived. If that's you, you'll be pleased to discover that many of the research skills you've developed as a genealogist can be used to track down building information. The records and information sources, however, can be different, and you'll need to acquire new skills as well. But that's all part of the fun.
If you're ready to tackle the buildings of your family's past, and if those buildings are or were in the five boroughs of New York City, you are in luck - as in so many other fields, New York City has an abundance of riches in documents and information.
On this site, you'll find basic information about building and property records in New York City. Learning by doing is definitely the name of the game.