Well if i were a boy, i would offer to help her hold her stuff or with homework or something like that. Or you can possibly put ur # on paper n slide it into her locker. I soeak from personal experience which means that os all the things my boyfriend did to me so i would like him. Just have ur friends ask her questions or anything like that.
The best way to get a girl to notice you, is you need to be yourself around her. Try talking to her just to establish a rapport. You can also complement her from time to time. Get some more tips on http://www.ehow.com/how_4724506_girls-notice.html.