It works like this fellas:
12 teams are placed in 2 six team groups. They play each team in their group once (round robin). After that, the top four in each group move on to the medal round which consists of an 8-team knockout tournament (quarters, semis, finals). The top seed in each group plays the four seed in the other group. The two's play the threes, etc.
There is a point system for qualifying, basically it is based on wins and losses, what the tiebreaker is after that, I don't know.