The best thing about those two is that they're BOTH available at night, too.
As for finding your own places, it's hard to describe it on a forum, but you can tell which girls will give you good day places and which will give you good night places. You'll learn to pick up on how they're dressed and such (i.e. if you can stop a girl in a summer dress, she'll probably offer a good day place... usually).
The reason I push for you to go out and ask people is because then when your friends say, "Hey, how'd you hear about this place?" or you need something to talk about on the way there, you can say, "Well, I actually took a weekend to go to the city *just* to talk to the locals about the secret nuances of the city. That's why I now know a lot more than the usual New Yorker might! This place we're going to, I had stopped these girls and..."
I don't need fake stories to keep up conversation because I made myself go out and find places on my own with their own good stories attached. Unless of course you want to tell them, "So one day I was surfin' the web hard core and this awesome guy named Tempus told me of this place..."
But I don't know how well that's gonna work for you.
Just remember this golden rule I live by when you're in New York and you'll see opportunities that no one else can: If it's before 2am, there's something interesting to be had.
EDIT: Use this to help you get around the city until you get used to the subway system.
http://70.107.230.223/
EDIT2: Okay okay, since you asked kindly I'll throw in a freebie (mainly because unless you ask the right people, you'll NEVER be told about this one =P). If you're into hookah bars, Google "Sahara East". It's an awesome atmosphere and, if you take the subway and walk there and are perceptive, there are plenty of conversation starters along the way.