I'd go for her chest first. And remember, the best thing for you to do is to take it SLOW! You don't want to scare the girl off or look like that's really all that you really want out of her. While you're kissing her, slowly start trailing kisses down her neck (girls love that). Then maybe start caressing her chest, making sure that you're gauging her reaction and try to keep the intimacy up. If she's into it, that's usually a good indicator that you can continue, but like I said, don't do too much at once. When I am dating a girl, I don't want to jump over all the hurdles (kissing, touching boobs through shirt, naked boobs, touching kitty through pants, touching kitty) in one night, because then there's nothing left to do but the deed! If you take it slow, you'll enjoy it more, and she prolly will to. Just my two cents.