The only issues with this overview is that it has dated and is somewhat UK-centric. It's split up into the basics of the philosophy followed by an overview of Buddhism's historical spread to the present day. It has an interesting Who's Who section, too. A good basic starter to further reading.
Highly readable overview of the major schools of Buddhism, their practices and history, and the state of Buddhism in the West at the time of the book's publication. (I'll admit to having skipped a chapter on Buddhism and Psychotherapy).