A word of caution. If you are looking for the DEFINITIVE guide to everything Batman, I wouldn't recommend this book to you. Les Daniels' book on Batman is by far the most comprehensive treatment on the whole history of the Batman from his pre-conception in the 1930s up till the recent stuff (including his incarnations outside the comicbook - TV, toys, cinema, etc.). Also, if you're interested in analyzing Batman as a pop-culture icon, you should check out Will Brookner's "Batman Unmasked" book. Finally, if you're interested in reading a one-volume collection of the definitive Batman - I'd recommend Frank Miller's "Dark Knight Returns" and/or "Year One" along with the "The Greatest Batman Stories Ever Told".
What then is this book by Scott Beatty about? It's about the modern day Batman. THIS Batman is as different from the classic Bob Kane/Bill Finger creation as the Tim Burton movies are from the Adam West TV show. For your information, THIS Batman is the one from Frank Miller's "Year One" (1986) and it includes the later revisions by Dennis O'Neil and Chuck Dixon up to today. In other words, this is the Batman of "Knightfall", "Contagion", "Cataclysm" and "No Man's Land". And in my opinion, this is the most exciting and rich version of the Batman since his conception in 1939. This book is not so much a guide but more a celebration of this modern-day Dark Knight of the comicbooks.
The book is neatly divided into sections. The first section is about Batman/Bruce Wayne and Gotham City. The second section covers his allies and loves (Alfred, Gordon, Nightwing, Oracle, Robin II, Robin III, etc.). The third section focuses on the many colorful villains in the Bat-mythos. Finally, there's also a foreword by Chuck Dixon, the man who, under the editorial-eye of Dennis O'Neil, pretty much shaped the direction of the Bat-books throughout the 1990s. Note: Dixon also teamed up with the author Scott Beatty on some other great works like the recent "Robin: Year One" and "Batgirl: Year One".