The most simple kind of skimboard you can get is a plain piece of plywood. If you don't want splinters its best to start with a skimbaord made of wood and covered lacker. These are very durable and affordable. To learn how to use your woody it is best to go to a beach with a gentle slope so you can control your speed. Below is a picture of T-Street in San Clemente at low tide.

When the wave comes up on shore wait untill it retreats to leave a thin film of water on the wet sand. (The picture below shows good position, though he will want to wait till the film is only about 1/2 inch before he starts.) Then throw the board diagnal to the incoming waves and run and jump on the board.

The picture at the top shows a good example of the long rides you can get going diagnal to the shore with a good wood board.

Once you get your skiming feet and get used to the feel of gliding along the shore, try starting your ride near the oncoming wave(as illustrated below). When the wave comes, lift the weight of your front foot to allow the board to rise above the whitewash. Then, lean your body in the direction of the shore and try to turn the board toward the shore. You can use this technique to get some fast rides on the incoming waves, and it will teach you how to control your board in deeper water.

Now things are really starting to get fun. And if you've stuck with it this long, you'll probably want to try a foam core board (pg3) .