How do I get pass being friends with a guy?

I have a lot of guy friends and some I like, but if one tells me he likes me or ask me to be his girlfriend I stop talking to them and get real nervous around them, I don't know how to get to the second level. How can I stop being so nervous? How can I actually tell a guy I like him or if he's cute, without passing out?How do I get pass being friends with a guy?
Get a wing man , that helps sometimes and when you are alone just say what you mean and usually the guy will like that you talk and listen and aren't nervous and everything works out. once you do it once you will get over it. :D