Definitely go slow. Start with the kissing, that's always the easiest, even though that can be pretty scary, too.
Make sure that if either of you get uncomfortable you say so, and that you make sure that you know what the other wants and vice versa. Dim the lights, turn on a movie or some music, haha, set the mood.
Before my girlfriend and I started dating, we started to make out on my couch, and before I knew it, she had me on my back on the couch.