All I can say is wow, I am impressed! I probably have read the best SQL Server book I've ever seen. The book goes to unbelievable details in explaining the product, especially the knowledge given about SQL Server's foundations, which is rock solid and a must read for everyone who wants or needs to know the inner workings of the product.
The quality of the book is excellent from beginning to the end and it won't be a disappointment. The author gives the reader tips about best practices and recommended solutions in different scenarios. However, the focus is to provide the solid ground for the reader to make decisions related to the product usage. And this book is definitely one of the best ways to learn the basis for such decisions.
Because of the chosen target audience, this book isn't necessarily the best bet for beginner users. It starts with so much deep information about the product foundations that that alone might scare off some developers. Luckily, it's not necessary to understand all to get understanding of the product, but the more you understand about OS foundations, the more you can get out of this book. So starting with SQL Server and this book only is the harder route. If you can make it, I can assure you you will know all you need to know about SQL Server's architecture but it can be a rocky road. Having another, usage-oriented book, with this one is a wise choice.
As was mentioned, if you need a true hardcode book about SQL Server, this is the one for you. In fact if I were you, I'd already be running to the book store. You wouldn't want to miss this one.