Coaches and Parents regularly have questions concerning the rules of the game. Although there are some differences for younger age groups and local associations, the official rules of the game can be found at the following. http://www.ussoccer.com/referees/laws-of-the-game (text) http://www.ussoccer.com/referees/resource-center/online-training (video)
The online training is geared towards referees, but I've found it is also useful for the rest of us. You have to provide an email address, but otherwise there is no cost in using this training.
I would also suggest reading the "GNWSA Rules Pocket Guide" which is located on the downloads page on the GNWSA website. It provides a quick reference of the rule differences for the younger age groups.