How do I flirt with this guy? HELP!?

The problem with consciously flirting is it freezes you in anticipation of the act. Don't flirt. Just be natural. Be a friend and discover what he likes. It's easier to talk to a friend than to a crush. When you know him better and he develops a healthy respect for what is inside your head, then that is the time when you can introduce a little flirtation. It would be easier to flirt with somebody when his body language is already familiar territory. You will be able to gauge where you stop with flirtation and start with camaraderie.