The New York real estate market is highly documented and followed. Here is a short selection of recent market reports, websites synthesizing current residential inventory & pricing, trade associations and news sites.
Market reports
http://www.millersamuel.com/research-reports
http://www.bhsusa.com/market-reports
http://media.corcoran.com/pdf/Manhattan_Q22013.pdf
http://www.elliman.com/reports-and-guides/reports
Residential inventory & pricing
http://a836-acris.nyc.gov/CP/ [Acris]
http://www.nyrealestatetrends.com
Trade associations
News
http://www.crainsnewyork.com/news/industries/real-estate