What should a girl do next if she likes a guy?

[Mandy]

I'm a 4th year med student and there is this guy I recently met during one of my rotations. We've had a few convo's here and there and he seems to be a really nice guy. So far he has initiated every convo we've had and most have been during our lecture days. I get really nervous when I talk to him and I think my nervousness might come off as being rude- I try to end the convo fast and I usually just start talking to someone else.Anyways, I've tried to show that I'm not a complete bi*** and I recently sent out a friend request to him on facebook- he accepted it! But now I don't know what to do. When it comes to guys I like I tend to get really shy and nervous. I don't want to come off as being weird or aggressive- but at the same time I don't want to miss an opportunity to get to know someone that I like, What should I do?