There is a kick-off to start each half and extra period. Just before the start of the game, the referee will call for the Captains of each team to come onto the field. The referee will then toss a coin to decide which team kicks off first and which goal each team will attack during the first half of the game. The winner of the toss gets to choose which goal it will attack and the other team takes the kick-off. The teams will then take the field and referee will ask if they're ready to start the match, and will signal for play to start, at which time the kick-off will occur. To start the second half, the team that won the toss takes the kick-off and the teams attack the opposite goal (so they switch sides of the field).
There is also a kick-off after every goal. Each time a goal is scored, the team that didn't score gets to kick off.
Kick-off Rules. At each kick-off, the ball is placed in the center of the "Center Mark" (on the half-way line) & both teams must be on their own half of the field (although it is usually okay to be standing on the halfway line) and the receiving team must stay outside the Center Circle until the ball is "kicked". Moving the ball any constitutes a "kick-off", even if it only goes an inch. However, the ball must move forward on the "kick-off". The "kicker" may not touch the ball again until someone else (on either team) has touched it (if he does, the opponent gets the ball and an "indirect kick"). However, the "kicker" may put his foot on top of the ball & barely move it forward so a teammate standing nearby can dribble it or pass it backward or forward. If the kicker touches the ball a second time before it touches another player, the opposing team is awarded an "indirect free kick". For any other violation of the kick-off law, the kick is retaken (the most common violation is a player on either team crossing the halfway line or the receiving team going into the Center Circle before the kick).
A goal may be scored on a direct kick off (i.e., another player is not required to touch it first), but it is better to not just kick the ball to the opposing goalkeeper because it will usually be easily picked up.
For the official rules, go to www.fifa.com, to "Regulations", then to "Laws of the Game".
Our recommended Kick-off for Rec teams. Don't spend a lot of time teaching fancy kick-offs; there are so few in a game that it's not worth it. For all Rec teams SoccerHelp recommends just lining up and kicking it deep to the corner so your Forwards and Midfielder's can push up and try to win the ball back. If you want, you can "overload" to the side you're kicking to, but you must be careful because that will pull your players out of position. But you can safely move the players on the "weak" side (which is the side you aren't kicking to) toward the center, which will prevent your opponent from easily driving through the center to your goal, put your players in a good position to win cleared balls and put your players in a good supporting position in case your team gets the ball on a turn over. Rec teams are more likely to score on a turn over (i.e., a mistake by the opponent) than on an attack starting with a kick-off. This kick-off has the advantages of being easy to teach and of moving the ball away from your goal so you avoid the possibility of turning over the ball in the midfield and giving your opponent the chance to score an easy goal on a quick "counterattack". Our experience is that it isn't worth Recreational teams spending much time practicing kick-offs (there aren't many kick-offs and there are many more important things to practice). Kicking the ball to the corner is a good strategy and you avoid the risk of turning over the ball and giving up an easy goal. In fact, many high school teams are now using this kick-off and most of the teams in the 2003 Women's World Cup used it. (See "Soccer Positions Basics & Kick-Offs" for examples of positioning players on kick-offs)