Actually, if I'm imagining you right, let me give tips from someone who's had a crush on someone for over a year.
First thing, become friends and talk to them. You can't just out of the blue say "hey you, want to go out with me?" With her if you're only an acquaintance. (At least, that's what I think)
Right then, second, learn about her personality. The girl I have a crush on is kind of shy and quiet, but she's funny and smart too. Basically, be sure that your crush has the personality you had hoped for.
Now... At this point things can go well, or they could hit rock bottom.
You could muster up the confidence and ask her out for a movie or something.
Or
You could drop her anonymous notes. Just to make her know "hey, someone out there likes me"
Then again, she could have a boyfriend, or she could be in the "friendzone", or she could just get creeped out by you.
I don't know, I'm still naive to this whole love thing. I promised myself to fly solo but this girl is just... Beautiful and smart. I don't know if I should pass up the chance.
Good luck with your adventures in romance though, we all need it really.