For the longest time, this city made me nervous! I really don't know why, but once yuo start exploring Manhattan you truly get fascinated about the Big Apple. Yes, it is expensive, and yes, it is bit crowded at times, but it is still exciting and very much a cultural experience.
As you can imagine, there are so many neighborhoods, and they truly are unique; whether it is dining, shops, or Broadway, there is so much out there.
Quick Tips:
Car? Fuggedaboutit! All airports are very accessible anyway via public transport--taxi or bus.
Stay in Manhattan, though, if you can, to really get a feel for the city. The closer you are to Broadway and certain touristy areas, it can be pricey. There are some reasonable hotels around, but remember--even the fanciest of hotels tend to have small rooms.
Best Way To Get Around:
In Manhattan, you will walk a lot, and you will probably take a yellow cab.