This is a really great 'best practices' book for Django developers of all skill levels.
In the Django community, there are a variety of practices that people tend to use: webapp structure, coding conventions, library preferences, etc. As a Django developer, finding out 'which way should I do X' is often harder than it seems: there are tons of articles on Google, but it's difficult to make sense of which recommendations are right.
This book takes a really great approach to the problem by introducing readers to a great deal of information: which way you should do X, why, and how it works. Instead of just getting a solution, you'll understand why things should be done that way, and how it works.
Furthermore, I can tell you that as an editor of this book, both Danny and Audrey (the authors) took quite a lot of feedback, and made a lot of progressive changes to the content. This (in my opinion) is a huge selling point, as you know all the book's content has been reviewed by numerous influential Django developers and users.
Anyhow, this is a really great book, and quite cheap for the asking price. I'd highly recommend you read it, regardless of your skill level.