Last weekend I visited my folks in Tucson to celebrate my sisters wedding. A good time was had by all and while out there I was able to enjoy our swimming pool. Tucson is still a balmy 100+ degrees so the pool is refreshing and if kept heated could be used year round, but back here in the Northeast most people are considering when they should close their pool for the winter.
This article from the New York Times goes through just the steps to do that. They recommend leaving the water in the pool throughout the winter but make sure that the pool is still protected from young children wandering in.