What are some good drills for a soccer (football) training session?

I am starting my first coaching job tommorow morning, and have no experience. I love soccer and know all the rules involved and I also used to play. I know alot about formations strategies and such and I also watch alot soccer matches on TV. However having no experience I am not sure how to start, it's under 12 boy team and don't how exactly to train them. If anyone can give me an idea of what a full session should be like from start to finnish I would really apprecieate it. Should have them stretch first than run some laps?