Still in highschool aren't you?
There's really no good way to go about it. I suppose you can let her hear through the grapevine that you like her, and wait and see what she does.
Or try and get her semi-alone and just lay out how you feel. It's entirely up to you how awkward it gets. Really, ask yourself why you're flummoxed by her. Are you afraid of being rejected? Do you doubt that you're worthy of her affection? Social awkwardness is about your hang ups, and defeating them is what allows you to approach others you're interested in. I'm all about aversion therapy in this regard. If you're afraid of talking to her, talking to her is the only thing that's going to help. And rather than beat around the bush awkwardly for as long as it takes to become comfortable, I'd just say it. "I think you're very pretty. So pretty in fact that I can't even think straight when I'm around you. I'd like to go out with you sometime, " Maybe she'll find it endearing, maybe she'll find it creepy, maybe you'll barely be able to squeak out a sentence. But at least you'll have done something, moved forward and combatted your own insecurities.
I remember feeling this about a girl in highschool. Had a group project with her, got to know her a little bit and when I finally asked her she went "pppfffttt, no." It stung like a son of a bitch. On the flip side, my next emotional reaction was to go "Wait a minute. I don't need this stupid, self-absorbed rich girl to know I'm likable. Fuck her, and the snooty horse she rode in on." Being rejected may not have been best for my confidence, but it definitely changed my thinking about rejection.