heh, I'm a gril in a relationship and I have a problem with flirting.
I'm just a naturally kind, caring, open, and touchy-feely person. A lot of people think I flirt with all my guy friends, but really I'm just being myself.
Lucky me, I have an understanding boyfriend. -grin-
There is no definition for flirting, no one set way to do it. Commonly, it involves a lot of nice smiles, sometimes a bit of touching (hand on shoulder, that sort of thing). Making her laugh is a start, but sadly in High School that's all that people do. EVERYONE lives to make other people laugh. -grumble-
But we're getting into my own problems. Back to yours.
School dances are great for pushing a relationship to the next step. It's amazing what one casual slow dance will do to speed things up. Oh, and don't be a stalker. Don't try to follow her around, don't plan for accidential meetings. The less she sees of you, them more special and interesting the times she DOES see you will get.
Lastly, be yourself. There's nothing worse than a bad actor trying to be cool, spinning unbeleivable stories about his weekend and whatnot. I gaurentee she will not be impressed.