Get to Know Him
Get to know your crush. Strike up fun, short conversations with him whenever you get the chance. Pay attention to his interests and concerns. Smile and try to flirt with him.
Find a common interest. Do not feign interest in something you could care less about just to impress him. If you can't find anything in common, the relationship may be doomed from the start. Stay true to yourself---don't change who you are to get a guy to like you.
Ask him out on a casual group date once you've found something you both like. For instance, if you both enjoy bowling, invite him on a bowling outing with you and your friends.
Be confident. Don't throw yourself at him or devote all your attention to him. Doing so will create awkwardness between the two of you and between you and your friends.
One on One Time
When you've gotten to know your guy better, ask him to hang out with just you.
Turn on the charm on these one on one dates. Exude confidence and don't be afraid to tell him that you think he looks great or to compliment him any way.
Tell him how your feel. He may have already picked up on your clues (or if you have talkative friends, they may have let him know how you feel) and may be ready to let you know that he likes you.
Back off if the guy doesn't react to your flirtations or seems uninterested in hanging out with you. Don't waste your time on a guy who can't see that you're a terrific person.
Give him space after you've told him how you feel. Don't call him daily or expect him to devote every waking moment to you. Furthermore, don't play games. You like him and you've let him know. The hard part is over.