Zen Meditation: Plain and Simple is an excellent little primer on how to sit in zazen. Also covered are the basics of Buddhism and Zen. The instructions are easy to understand, and the explanations are concise if slighly dry.

The only drawback is that the pictures showing the positions are in black and white, and the model is wearing dark clothing and socks. This makes it very difficult to tell the difference between the Lotus and Half Lotus positions if you don't already know.

The book stresses persistance, and that "anything brought up by zazen can be solved in zazen". It is a simple, fairly undogmatic approach to the practice of meditation.