The layout of this book is extremely well considered. Depending on the reader, one can focus on the user, admin, or programmer section. The theory is also presented in a separate section with an appropriate level of background security information (you might want to read this section first if you don't have any security background).
The writing is also very well done. Dr. Tung never repeats himself (unlike other technology authors) and his examples are short and to the point. The reader is even, occasionally, treated to a delightful sense of humor. I certinaly hope that Dr. Tung will produce more books.
I recommend this book to anyone, period. Of course, if you are using or developing Kerberos apps, then I really, really recommend it. Any system admin worth his or her salt should read this book as well, even if they are not currently considering Kerberos.
My final thought: this book would make a great stocking stuffer!!!
Dr. Matthew Presley, Chief Scientist, QB, Inc.