My main purpose in purchasing this book was to prepare for the Word 2010 Expert certification exam (currently in Beta mode). Microsoft recommends the "Inside Out" series for the Expert level certification exams.
What makes this a tough book to learn from is that no practice files or follow-along content were developed for this book. This is pretty standard practice for these types of books, especially from Microsoft Press, so I was really surprised no such material was developed.
So unless you have lengthy personal documents handy where you can practice making bibliographies, indices, etc., you're left trying to apply the concepts to whatever Word documents you have lying around on your hard drive. Although I did well on the test and probably would not have done so without this book, I spent far more time than I should have on learning the content, because I often had nothing on hand to which I could apply the concepts.
Macros- this book does not prepare you to learn VBA, a subject area for which I bet some people will buy this book. It's well known that no "gold standard" book on Word VBA exists, but all this book does is spend a few pages describing how to record a macro and how to navigate VBE, then directs you to the Word MVP group website to learn VBA by reading posts. The book completely dodges any serious attempt at teaching Word macros.
I also have to point that I ran into more grammatical and spelling errors in this book than I've ever come across in a technology book. Not what you would expect in a word processing book!
The free ebook is a very nice touch (requires free registration on Safari Books Online, well worth it to access the ebook).
I passed the Expert test and this is the only book I used for studying. I started out with a decent working knowledge of Word but without this book I would not have passed the exam.
If you are trying to get Expert certified in Word, this book will do the trick, as long as you stay extremely patient and apply all the concepts while following along. Just grab the longest Word document you have available and you should be able to find ways to make it work.
So I give 3 stars because I have to ding it heavily for lacking practice files and a thorough discussion of macros, offset in part by coming packaged with a free ebook version and the fact that I was able to use it to pass the test.