There is a wading pool, I think it's out next to the Bay pool. There is a playground in the courtyard of one of the garden wings, you can't miss it.
There are two pools:
The Main pool with water slide and two jacuzzis'.
The Bay pool which is a circular pool, that is shallow around the edges, and get's deeper as you go towards the middle.
If your kids are the type that love swimming all day, I'd recommend you hop on the monorail and head over to the Polynesian and Grand Floridian pools. They have a beach type entrace area to the pool, where it's like a beach and it's shallow enough for the children to play in. And they have all the lounge chairs in front of this area, I've seen many parents put their lounge in this water/beach area to watch the kids.