The ground around my pool is one area I wish I had planned more for before i put the pool in. After having the pool in one summer with just sand around it, I put in white limestone last summer, running about an 8 inch radius around the pool. It looks nice, but if I had it to do all over, here is what I was thinking:

1) Clean out a channel around the pool about 1 foot wide.
2) Put down a layer of weed barrier
3) Put down a thin layer of pea gravel
4) Top pea gravel with limestone (I like the look I get from the white limestone)
5) Between stone and grass, I would bury at ground level small brick paving stones. The stones would sit low enough that I can run the mower wheel across them.

Just my 2 cents..