How do I let a guy know that I'm really into him without being overbearing or desperate?

No need to tell him anything, just say hello and get to know him better, ask if he'd like to go out some time, and see a movie.

Go fro there, it's not rocket science, just two people going out on a date. Be prepared for rejection, in case he doesn't feel the same way about you. That's the only risk, and we men do that all the time.

well i would just tell him but do it face to face to see what heppend and what he does. its teh best way and if he likes you you know and if not then leave it alone for a better time