I've acquired a number of books on my favorite television shows over the years. For the most part I've learned to avoid the "official" guides or companions, because more often than not they tend to be antiseptic, unilluminating, and uncritical. But just as BATTLESTAR GALACTICA is a brilliant exception to what one normally finds on commercial television, so this companion is a delightful exception to the typical "official" publication.
There are several reasons for why this guide far surpasses the usual guide. First, too many guides merely tend to regurgitate the contents of each episode, add a few quotes from the episode to fill out pages, and then perhaps identify the music used on an episode. If you are lucky, you'll learn what previous shows guest stars have appeared on. This book, however, truly is a companion. It actually provides very little in the way of summing up individual episodes. In fact, the average length of space devoted to summing up the events of a show is less than a page. This means that in this 157 page book only 15-18 total pages of text is devoted to summarizing the events of the miniseries and the 13 episodes of Season One. The rest of the book is filled with a wealth of supplemental information, such as explaining the genesis of a script, of major changes it underwent before shooting, of changes made in an episode following shooting, of decisions made in altering the special effects, and so on. There are also many quotes provided by the show's many actors, who were clearly interviewed especially for this book.
There is also an openness in this book that is quite refreshing. For instance, it reveals how specific actors turned down particular roles (e.g., Lucy Lawless turning down the role of Ellen Tigh). There is a great deal of information provided on the casting process and who was responsible for discovering which performer.
The book not only deals with the background to each individual episode but also with how the recreation of the 1978 show developed. Individual chapters explain such things are the special effects work on the show, the music, and the art design. Substantial summations of each major and many supporting characters are provided at the end.
As a result of all these factors, this is easily one of the most helpful and illuminating season guides I own to any television series. I strongly recommend them to any fan of the series. I will only add that a couple of reviews suggested that the book doesn't provide much for a serious fan. I've watched the entire series at least five times, I have read exhaustively on the Internet, I have made hundreds if not thousands of posts about the show on various forums, and have listened to all of the podcasts and commentaries. But I learned a great deal from reading the book. So I think it safe to say that this is for serious fans as much as casual ones.