It's just one pool, and its all the same depth, quite deep for little ones, my two (aged 5 and 3 last time we were )there couldn't stand up. Having said that there are plenty of floats etc for them to use. There is also a slide, and a spa pool I think, though we disnt use that.
The water wasn't very warm either, as it adjoins an outside bit of pool which was closed off by some doors, but still made the water a bit on the chilly side in feb!
There are lockers in teh changing rooms I think, and I remember the changing area being quite small.
We have used it a few times, so it can be that bad. Make sure you take warm clothes if in winter as you have to go outdoors to get back to your hotel room.