I have written a chapter-by-chapter review of this book on i-programmer DOT info, the first part of this review follows:
This Book aims to provide solutions to the most common problems encountered by the inexperienced (accidental) DBA. How does it fare?
The premise behind the book's title is that many DBA roles are filled accidentally, often by the developer that has the most database knowledge. This typically results in a steep and stressful learning curve, as mistakes are made. This book, which can be downloaded as a free pdf file from www.red-gate.com/community/books/accidental-dba aims to help the accidental DBA overcome the most common problems.
The book was published in September 2011, and covers SQL Server 2005, 2008, and 2008 R2. It occasionally drops back to SQL Server 2000 and jumps forward to Denali (the name of the beta version of SQL Server 2012). Although SQL Server 2012 is not covered explicitly, I think 95% of the book is still applicable to SQL Server 2012.
Considering how much it covers, this is a short book, it could have easily been twice as big. Luckily it concentrates on what you need to know, and provides useful links for further reading. In many ways its limited size makes it more difficult to criticize negatively. The first seven chapters (of nine) read like a guide to performance tuning and troubleshooting. So it comes as a surprise when the last two chapters switch to admin related issues. Some useful code is supplied, while it is adequate for the introduction of a topic, if you want to delve deeper you will need to rely on the chapter text to extend the code or look elsewhere. One small gripe is the lack of diagrams and outputs...