Cheer up! A lot of college students are totally inexperienced when it comes to kissing, dating and sex. As a girl, I actually prefer guys with less experience, and most of my female friends would say the same. I assume that the more women he's been with, the less likely he is to take love and relationships seriously. Some guys may boast about having a lot of experience with a lot of different women, but chances are that if they've been with so many, they probably haven't had much luck in keeping one.
If you like this girl and you have the feeling she likes you too, just take it easy and wait for the right moment. Nothing's worse than trying to force yourself on someone at the wrong time. You don't necessarily need to start out by telling her you've never been in a relationship before, unless you get comfortable enough to talk about such things with her before you actually kiss or share any physical contact.
I suggest you take your time with this one and get to know her better. As you get closer, things will just naturally begin to develop. Hang out with her more, make your conversations more "personal," be friendly, but show her you're interested. You can do this through body contact and eye contact. I usually get the hint when the guy will give me a quick rub on the arm or pull me in for a quick hug when he says "goodnight," or if he looks deep into my eyes when he's talking to me and pays a lot of attention to my lips. If you try with some casual body contact, you can usually work from there. Strike up a conversation about relationships and see where it goes. That might be your chance to mention that you've never been in one, and add that you'd really like to be (without being too terribly suggestive). You could try by talking about one of your friends' relationships and something that's good or bad about it, then saying something like, "I kind of wish I knew what that was like because I've actually never been in a relationship."
The odd girl may find it strange that you've never been with anyone, but the vast majority will just think it's adorable and you'll probably win a lot more points than if you went off comparing your various ex-girlfriends.
You don't have to tell the girl you haven't been in a relationship/you haven't kissed a girl before you decide to kiss her. If you get the sense she's warming up to you, try this: when you get the chance to hang out alone in a more intimate setting, just let your conversation go quiet and work with your hands. Don't talk. Run your fingers through her hair and rest your palm on her cheek. If she lets you hold her like that and the reaction is positive, lean in and kiss her. If she doesn't seem to like it, drop the hand down, apologize, and then you'll know it was a bad time or she's not interested. After you kiss her, you can tell her you've never done it before. If you bump heads or something embarrassing happens, don't worry. Not all first kisses are the stuff of Hollywood. Mine sucked, but I've had some really amazing kisses with other people and the first one is practically forgotten.