A Victory is worth 5 Points
A Loss is worth 1 Point
A Draw is worth 3 Points
A Bye is worth 5 points (kind of a "sorry you don't get to play this round kinda bonus).
If you don't play (or record your game) before midnight of the start of the next round both you and your opponent receive 1 point as a loss.
If your opponent forfeits you receive 5 points as a win and your opponent recieves 1 point as a loss. Vice versa if you forfeit. Make sure that if you are the reason that the game can't commence that you click the forfeit button rather than just wait it out. It's not fair to your opponent.
At the end of the league the points are tallied (okay, they're tallied each and every time a battle is reported). The winner is the player with the most points. Ties are broken by using the "Strength of Schedule" concept. In other words: the person who played against the people who ranked highest in the league will rank higher than those who played against lower ranked players. This value is calculated at the very end of the league so if you're looking at the results right now (about a week before the league ends) you'll see there's contention for the 2nd and 3rd place prizes. Strength of schedule will adjust the rankings so there shouldn't be a tie.
Now that the leagues are running pretty well without a whole lot of intervention from me, I'm going to be putting in some code to allow for alternative scoring mechanisms and the like.