don't go telling her suddenly everything you feel. try to impress her somehow, but pretend you don't care much about what she thinks about you, even if you care a LOT. talk to her often, but not the whole time. in general, if you speak too much, she's gonna see just a friend in you, a confident, and you want more than that. then, after being pretty closer to her, invite her for a date (but don't say its gonna be a date, even if she knows it will be). there are plenty of places you guys can go, like cinema or just go for a walk. if so, tell her "there's a movie i'd like to watch, it seems to be great" (try to look as casual as possible!), then ask her if she wants to watch it too (i used the movies as an exemple, but it can be anything else). then, it's up to you. tell her you like her very much, and you are glad she is with you that moment. if she likes you, she'll accept your words. if she doesn't... welll... at least you tried. but don't give up.

Grow some balls and go and speak to her. What's the worst that can happen?

This reminds me of high school. Anyway, here is my tip. Be yourself, and try not to act so hard and go up and chat with her. Girls love good looking guys but if you are not, humor is your way to her heart. Never ever express too much about how you feel about a girl. If she doesn't like you, and you suddenly tell her too much stuffs, she will think you are a creep. If she likes you, she will want to continue to chat with you...thats the smallest sign.

Talk to her, she could feel the same way about you, and if you don't talk to her you may never know what could happen.

Grow a pair!