Keys to the Rituals, Symbolism, Magic and Divination
The New Golden Dawn Ritual Tarot
The book consists of roughly three sections. The beginning contains the authors' approaches to the Golden Dawn teachings regarding the Tree of Life, a brief history of the Golden Dawn in the United States, and related topics. This is followed by a description of the cards (as the Golden Dawn saw them). These are followed by ritual discussions (LBRP and related rituals, opening by watchtower, etc). Finally divination is covered.
All in all, this book is a very good introduction to the Golden Dawn approach. It is more accessible than anything Regardie wrote, for example. All in all, recommend this book to those looking for such an introduction.