Like FOOTBALL? You'll LOVE this site. (Thanks Will for recommending this one.) http://www.nflrush.com
Sports Illustrated for Kids http://sikids.com
Baseball anyone? http://mlb.mlb.com/mlb/kids/index.jsp
A variety of team sports beyond the "Big Four" http://pbskids.org/itsmylife/body/teamsports
Kids World Sports by PBS http://pbskids.org/kws/
GO TAMPA BAY RAYS! http://tampabay.rays.mlb.com/index.jsp?c_id=tb
Get the basics on lots of sports at The World Almanac for Kids. http://www.worldalmanacforkids.com/WAKI-Chapter.aspx?chapter_id=13