I think this guy likes me (obviously I like him) but I can't be sure? Should I ask him out?

Okay, so we've known each other for 2-3 years and have started talking on a regular basis about a month ago. Whenever we talk, he'll look me straight in my eyes the whole time, smile at the things I say, do anything to make me laugh and sit a little closer to me than most people would. (just to specify, we both just ended our sophomore year in high school). Whenever he's talking to someone near me, I'll catch him glancing over at me. I've also caught him looking at me in English and band on numerous occasions. he also seems to comment on anything he happens to hear me say to a friend. Finally, we have almost everything in common (Mel Brooks, frank Sinatra, SIM freaks, AP class overloads, etc.) and he kept saying I was a really rare type of person yesterday when we were playing at commencements. I'll be able to see him next week when marching band starts :) do you think he likes me? I'm pretty positive he does, but you can never be sure. If he does, how do I ask him out or get him to ask me out? I'm not very experienced as far as dating is concerned... Thanks :D