Posts: Curling?

Before the Olympics started I never really even heard of curling, now I've decided that curling is one of my favorite winter sports (I have only watched 4 times). But, I still don't really get the full meaning but I think it's starting to come to me (I am just guessing), slide the rock down the ice. It's sort of weird to watch the curlers call time-outs an plan their next move when you don't even know what the point of the game is. Also, I don't understand how 'sweeping' in front of the rock could make the rock curl. If anyone is a curling expert, please help explain this to me, for I am at a loss.