You can take two approaches obviously...the direct and the passive. In this particular situation, I would take the direct simply because beating around everything yields worst odds regularly than if you take the situation head on. Now, I'm not condoning slamming her over the head with how much you are head over heels for her but seeming casually interested is certainly not poor advice.
Get a relaxed moment to break some ice with her and speak to her as a friend. Achieve some type of reciprocating dialogue and then simply ask her if she would like to go out or accompany you to a particular place.
This will undoubtedly set up more dialogue and you can proceed from there. However, sincerity is going to be the key here so don't forget that aspect of the puzzle.
Take care,
Brian,
http://valueprep.com