Our local YMCA offers a Backyard Pool Program, where they'll come and give you lessons in your own pool. You don't have to be a YMCA member for this program (although members get a lower rate), and it was one price for up to 6 students. I signed my kids up, and my SIL brought her two kids over for the lessons. They had a total of 8 half-hour lessons over two weeks (Mon-Thurs; they keep Fridays open as a rain date), and I'm really glad we did it. My daughter, who is 7, now jumps off the diving board, can swim across the pool, and can swim down to the bottom of the deep end to retrieve things, none of which she could do earlier without a swim vest. My boys had previous swimming lessons, but this gave them a refresher, and they're much better in the water now.