I was a soccer mom for many years (and DH was soccer dad!) - both boys (now late teens) started out on town recreation teams in the fall at age 5 and by age 6 both were chosen for the town's "competetive" teams in their age groups, which were "travel teams". They loved it and we all had a lot of fun....it became a huge part of our life, and we made many friends by meeting the other parents/families. But.....
Word of warning - follow your instincts. People get caught up in this...you'd be surprised how many parents of grade schoolers talk about their child getting a college scholarship for soccer, and they place tremendous pressure on their children. It was difficult listening to comments parents would yell out to their children - ordinary nice people become tyrants sometimes. Some coaches also do not have the children's best interest in mind -their mindset is to "win at all costs". Our older DS was fortunate to always have compassionate coaches to teach him not only the game, but also good sportsmanship. They did this by example. Our younger DS seemed to get the extremely competetive and loud coaches - the screamers. This DS was a very good goalkeeper -he was chosen to play on a premier team for the state, and we traveled out of state for many tournaments. Other teams coaches would come up to both him and us to comment on his skills....and locally a few tried to recruit him. He burned out at age 14...he had developed a nervous twitch and when we sat him down to discuss everything, he finally admitted it just was no longer fun. We allowed him to get off the team immediately, having always told both boys it was their decision when and what to play. He took a breather from team sports for a few yrs, and now at age 16 1/2, is playing golf and absolutely loves it. He made the cut to the HS golf team, and is a happy, relaxed kid -very different from the child of a few yrs ago.
One example -he was in a game one time, and another player on his team received a yellow card for some offense - this meant he was not able to play in the next game during this winter tournament (when games are all held on the same day) . The boy was a talented player, and the coach worried the team would lose if he could not play...so before the next game started he told another player to switch jerseys with this player, so he would be wearing a different number and the ref would not know the difference, since they go by numbers and not names. Well, lo and behold, the kid switched jerseys, went out on the floor, and out came the SAME ref from the last game!! Coach pulled this kid out very quickly, before ref noticed. Can you imagine what this is teaching the players? And more unbelievable, only 2 sets of us parents saw a problem with this -and we both spoke with this coach and then reported the incident to the league.
So....team sports are wonderful and can be character building, under the right conditions. Just beware and keep your eyes and ears open, and listen to your gut instinct and your child, and don't ever be afraid to voice your opinion. Allow them to have fun, learn the game and the sportsmanship that goes along with it, but please always remember and remind your child - IT IS ONLY A GAME!!!
Another soccer mom here. MY DS LOVES soccer....how can he not when he grew up in Italy, the land of soccer. DS just spent last week at soccer camp and declared it one of the best weeks he has ever had. Also at the end of the week he was given tickets to the local pro teams game, which we went to this weekend (DS loved it, DH and I on the other hand were glad it was free). I don't know what kind of advice to give you, just let your child have fun!!
By the end of last season I thought he was going to lose it. He would get out of work early for a practice and 3 kids would show up(he took 2 of them). 
