Before reading this book, I had tried out OpenBSD a little, but I was left with many questions, and online documentation can be a bit intimidating at times. So when I found this book at the bookstore, I was thrilled. I am happy to say that this book really did live up to expectation.
The intended audience of this book were people who knew there way around Unix and Linux. One need not be a veteran user, but as the author points out, you are expected to know basic command line stuff. If you are there, you will find this book to be a very easy going, yet thorough introduction to OpenBSD.
This book walks you all the way through the origins of BSD, through installation (an excellent section of the book), to usage, compiling kernels, and so on. You get a well-rounded coverage of a very interesting operating system.
I also really like the author's style of writing. On the one hand, you get a genuine sense of professionalism, but on the other hand, he cracks some good jokes throughout. If you are a system admin of any sort, you will certainly appreciate the humor.
In closing, I would definitely recommend this book to anyone who's had some experience with Unix and Linux. OpenBSD is a operating system few have tried, but I think after reading this book, you will definitely want to go out and try it yourself. The book is definitely time and money well spent.