See if they have a water aerobics class! Our Y offers both a shallow and a deep water class. You don't need to necessarily know how to swim or anything and get a comfy, one piece suit. The chlorine in the pools will fade your suit very quickly so just get a cheap one for working out until you know you will stick with it. Then they have some suits that are chlorine resistant and gaurenteed for like a year!
-------------------- Taking it one day at a time.....