I have been using OpenBSD for over 12 months and wish I had this book by my side when I started.
The book provides a good introduction to OpenBSD and guides the reader through the installation and configuration process. It is best read with a spare computer system by your side so you can try out what you are reading.
Whilst I know the bulk of the contents of the book having previously read the relevant man pages, I did learn several new tricks as well as gaining a better insight into areas I am familiar with.
The book covers the latest OpenBSD 3.3 version.
So I would recommend this book to a UNIX newbie and also an experienced UNIX user. The book will be staying on my bookshelf as a convenient reference.