Three pieces of equipment are essential, for working on your movements and strengthening your muscles. You probably learned to swim with a float, they are a great way to do kicking lengths for leg strength. A pull buoy is a small foam float that you grip between your legs while you swim, to work your upper body, and paddles and gloves enlarge the surface of the hand for more resistance, to intensify your work-out.
-Zip Paddles, Aquasphere
Easier to use than paddles, gloves also make your arms work harder. Choose a neoprene pair for maximum comfort. Available in sports shops.