If you know nobody in New York then you don't know what to do and where to go. But there are many people can help you. They love to talk about their city. And they do it every day.
Where to find them? At NYC Bloggers. This is a gateway to NYC bloggers' web sites. The web site says it has indexed 6364 different blogs. The good thing is that browsing them helps you to make yourself familiar with the New York subway system.
Once you find some blogs you will also know where their authors live, in which neighbourhood. Talk to them and ask them about different things about the city.
I like NYCBloggers.com very much even they still have not indexed NYC Addict.