Need tips on teaching kids to swim

My son is 6 and my daughter is 4. Took them in the pool, and decided we'd work on basics before they could just play. Practiced floating on the back a bit, although they're not good at it. The biggest shock was when I said we'd try without the floaties. My son actually swam for 15 seconds. It was really only a short time, but he was much more sure of himself. I got both to jump of the side of the pool into the shallow end, and I swam them down to the deep end and showed them the hand over hand method of moving along the wall. All in all, it was kinda of shocking how well they did. (of course I did bribe them a bit. :oops: )

Thanks everyone for the tips everyone, I feel like a have a better grip on this!! THANKS SO MUCH!! :D