Soccer rules are established yearly by the International Football Association Board (IFAB) for the entire world. Minor changes are made to these for the youth side of the game. Each league slightly interprets these depending on the level of play and safety of the players.
As coaches, it is your responsiblity to be aware of the Laws of the Game, their respective interpretations by the leagues you are playing in, and ensure that your players are familiar with them also.
Located here you will find various links with updated information on the Laws of the Game.