what three stories does the author say he will tell?

I do not have a copy of the book handy, but it seems to me from what I am reading that the book tells the story of the soccer team and their adjustment to small-town Southern life, the story of the coach and her challenges, and the story of the town and how they dealt with the team as they confronted all of the political, social, and racial issues. Lots of good information out there if you just search the title.