I heard about this service on a podcast. Never used it. It also is of questionable use in NYC where there are brokers. Still, if you are ultra hands on, might be worth a look.
NYC going soft on Bad Landlords
One could say this is a primer on how to scoff at the city.
Fire Escapes
Not everyone has fire escapes but good info to know if your building has them.
https://www.nyhabitat.com/blog/2015/11/23/5-things-know-fire-escapes-renting-apartment-nyc/
Facades
See this guide to Facades by NYC.