I'm a girl inlove with a girl, how to tell her?

I'm a girl and I'm a ninth grader. I moved to another school after seventh grade. There is this girl in my class, and I'm crazy about her. I try to hang around with her, and touch her back. Yesterday we were told to do a certain excercise together, and when I sat on one desk with her, it felt so great. But her best friend, a girl, always snapps at me, I belive she hates me a lot. Although it might be jealousy, I don't know. I dunno where the girl I love lives, We are not very close, although I'm trying to. Every time I ask her if she's free to go out, she denies, and explains that she's got some work to do, but I think she doesn't want. I'm afraid to talk to her about it at school, because I think everybody will know and start mocking me. I want to confess my feelings to her, but I don't know how. I also belive she might have a boyfriend, on her skype profile it's also written things like 'In love' or the /love/ emoticons. I can't stop thinking about her, I must tell her, but I don't know how. Please, give me an advice.

You can't just pick out a face in the crowd and "fall in love." A relationship that works is a mutual thing where both of you feel the same way. If you've asked her out and she continually refuses, that doesn't sound too promising. When someone likes you as much as you like them, they will jump at the chance of spending time with you.