Soon to be Relationship?

Alright, this is all going to sound a bit high schoolish, but whatever here it goes.

At age eighteen I've still never been into a serious relationship, just casual dating really. I didn't want to be tied down to someone throughout high school, and really I'm not a very boy crazy person, there's really only one guy that has really floored me. Anyway, I have this guy friend that I really like and it seems he likes me too. He always goes to make a move, but then wimps out. For instance, on Friday night we hung out and were watching a movie at his place and he kind of did that cheesy stretch of the arms and had one around me, but not touching me. I could tell he was about to put his hand on my shoulder, but then wimped out.

The thing is is that I'm not all that sure how to approach this, because like I've said I've never really been in an extensive serious relationship. I think we're both just too shy to make a move, you know? My friends tell me I have the tendency to give off an ora that I'm not interested. This has me so worked up that I'm getting sick over it, because I do have stomach ulcers and when I get worked up on things I get really sick.

I think my problem is is that every sort of relationship I had when things seemed to get a little more serious I shied away. Also, my best friend used to fancy him a lot and he kind of liked her, but he never pursued anything. I don't want that to happen to me, to kind of get led on and get hurt, but he does things with me he never did with her. He'll find excuses for us to hang out. Like now we have this thing where I'm teaching him how to play guitar and he's teaching me how to become pro at guitar hero, or will come into my work, or if a band I dig is playing at Gilman he'll call me up and say he wants to go. Just stuff like that.

Sorry that there's a lot of contradictions in there and a dose of high school shit, but I'm just unsure of what to do.