Please visit the below links to get more information about becoming a certified referee.
Idaho USSF Referee (General Information on becoming a USSF certified Referee)
US Soccer Referee Program (General information including the Laws of the Game):
Idaho assignor (registration with local assignor, fees paid, upcoming tournaments)
Please take the time to view this video which is less than 30 minutes. This will give you some good instruction as a first time referee:
Thanks and see you on the pitch!