5x5 means 5 hitting categories and 5 pitching categories. Typically these are BA, HR, R, RBI, SB for hitters and W, K, WHIP, S, ERA for pitchers. These are standard roto (rotisserie) categories. If you have 10 teams then for example, whoever ends up with the most HRs, gets 10 points, second most, 9 points, etc. Add up all the points you have in the 10 categories and whoever has the most wins. As far as playing for money, I am in a league with a bunch of friends and friends of friends. We each pay $100 at the beginning of the year and the top 3 finishers place in the money. I think its fun and at the very least if you do well you have some little reward for spending 50 hours on draft strategy and 30 min each day for 6 months setting up your rosters, attempting trades, monitoring your teams. Also, a little secret is to pick a couple players on west coast teams, that way, when you are out at a bar that sucks at least you have a vested interest in the baseball game on TV...sure beats, you know, talking to girls.