There are three different account types; Leagues, Team Coach and Player. Each account type has it's own benefits so make sure you pick the account that is right for you. And yes, it's absolutely FREE to sign up to SoccerAP.
If you are the coach or manager of a grassroots team then pick this option. You will be able to create a page for your team and update it as and when you want. You will be able to see all the players in your team, manage your team pages, upload team photos and much more.
If you play for a team then this is the option for you. With this account you can communicate with other players in your team, update your status, comment on other peoples pages, upload photos, and a whole host of other things. Choosing the 'Player' option also creates you a virtual transfer value that you can increase in various ways. Where do you rate on the transfer value leaderboard?
Leagues can also sign up to SoccerAP. They can create their own page and post on their own news feed. Every club and player has to associate themselves with a league when they sign up. So this allows the league members to keep the players and teams up to date with what is going on. Leagues can only communicate with teams and coaches within their own leagues.
All accounts give you options to search for other players, teams and leagues. Make new friends with your rivals or 'brag' about your achievements and so much more...