The explanations are clear and (mostly) concise and the material is covered in a logical progression.
I found it very useful and would recommend it.
I thought the book got off to a bad start with its introductory SQL chapter. Frankly, I thought it was a waste of space. It's neither fish nor fowl. If you already know SQL, it isn't necessary; if you don't already know SQL, you are going to need a lot more detail than this chapter contains. It would have been far better just to make a knowledge of SQL a prerequisite for this book and recommend a couple of good SQL books.
Having got over that however, the rest of the book is very good. The explanations are clear and (mostly) concise and the material is covered in a logical progression. For most tasks, Byrne explains how to do them using both command line utilities and the GUI tools. In the latter case there is good use of screen shots to illustrate what you should be doing.
The book starts with a good explanation of all the logical structures of SQL Server and all of the various files and devices involved. It then drifts slightly towards programming topics by explaining the mechanisms used to ensure data integrity and consistency. It then quickly returns to DBA territory with a chapter on the mechanics of actually starting and stopping SQL Server.
There is a reasonable, though far from exhaustive chapter on Optimising Performance. Given that a full coverage of optimisation would require a book on its own, Byrne has done a reasonable job of sifting out the basics. The next chapter is on Security. It explains how to use both NT and SQL Server security systems, how they interact and which should be used under common circumstances. Again, there is a lot more that could be said, but this is an adequate introduction.
The book concludes with coverage of Backup and Disaster Recovery. There is a good explanation of how to use the features of SQL Server for backup and recovery. There is also some coverage of hardware considerations, such as the use of RAID, mirroring and Uninterruptable Power Supplies.
This book is not the 'Bible' type of book that contains everything you could possibly need to know about every aspect of the product (and some that you could well do without!). Rather, it is a reasonable coverage of the major topics that you will need to know if you are going to be responsible for installing, setting up and maintaining a copy of SQL Server. I found it very useful and would recommend it.