I personally take a different side then Flyguy and RkTek. I'm not saying one is wrong or better than another, it's just what I prefer...
I do what I want. When I want to do it. But in your case I don't think it would do you any good to 'tell her' that you like her. I would say that I'd like to take her out to get something to eat. If she accepts then say "Good, we'll have fun. I'm starting to like you". That'll work just fine. Or you could go overboard and say something like:
"Hey, I have a feeling we're going to get married. And when we're 80, still holding hands and talking about our first date, I want to make sure it was really great. So lets figure out something really really exciting to do tonight, because who knows I might propose to you"
Some "DJ"s are probably gasping as they read this...but that's the difference between them and I. My advice is to do what you want, and say what you want - just avoid being too serious about it ONLY because it might make her feel a little uncomfortable that you're so forward. If the attraction is there, just roll with it and make something happen. If it's not you'll know because she'll make bullshyt exuses as to why she can't go out. Remember that girls who are REALLY interested in you HELP you plan dates...
-Blitz