If you already know how to swim and want to improve a bit, the book listed on Amazon gives some good pointers but isn't a keeper. Try borrowing it from someone or checking it out from a library. I'm too lazy or impatient to do the exercises since I'm not interested in competitive swimming.
You're better off a) swimming until you're comfortable in the water, b) spending the money on two or three adult swimming lessons with a good instructor (tell them about the swim test you're preparing for), then c) practicing, practicing, practicing...to build muscle memory. I also try to just focus on one or two techniques at a time.
What I recall is
- try to lengthen you body (swim tall) and keep it horizontal. Think of yourself as gliding smoothly through the water like a ship's hull, fish, dophin, or whatever works for you.
- keep the entire length of your body aligned (head included) as you swim, don't just move your head or arms - this means you will be rocking a bit as you swim in freestyle/crawl, and your shoulder and maybe hip will break the surface when you take a breath.
- when you flutter kick, try not to break the surface of the water often, if at all
- when stroking, cup your hands to maximize water resistence (power), and when positioning for the next stroke try to minimize water resistence so you don't slow your smooth glide through the water more than is necessary. I believe the book goes into the specific pattern of the stroke for freestyle, but any competant swim instructor should be able to go over it with you. In freestyle, you do not have to windmill stroke above the water...it wastes energy...just kind of ooze your arm forward just above the surface and then slip your hand back in the water fingertips first (hand cupped to power the stroke, of course). In breaststroke, when repositioning to stroke again, bring your hands together palm to palm right below your chest quickly but smoothly, then slide them forward. You just rotate at the wrist (thumbs inward) to stroke again when your arms are straight.
- Your head does not have to go all the way underwater in breaststroke. In fact, it should be horizontal (looking at the pool floor) between breaths so that your body will be horizontal. (Think this was from my swim instructor rather than the book).
