L.P.
We have had several pool parties, lots of fun. Swimming is pretty much the entertainment so I wouldn't worry about much more. We had a volleyball net and some ride on motorized pool toys to play on (don't recommed those at all - we only had 2 and everyone wants to ride them and they go thru batteries way to quick). I bought beach balls & water guns and the kids were allowed to take those home as "gift bags". Definately, INSIST, don't request that the parents stay with their child!! At 5 y/o you shouldn't have too much of a problem with that. When the kids get older, to the point where parents no longer accompany them to b-day parties, we would hire a certified lifeguard anytime there was a get-together or party involving the pool.