This is rare book because most of the parts in ArcPy is covered. You can learn from how to set up python environment to how to create your own toolbox. Even after you read through this book, you can use this book as encyclopedia for ArcPy. The only one problem is monotonicity. Through chapters, the author show the code without any real-world analysis. So you may feel boring at the middle of this book. To avoid falling into such a pitfall, I recommend you to pull the real data from the web and apply it to the codes shown in this book.
Finally, As is clear from the tittle, this book is exclusively for the people who are using ArcGIS, not for people who wanna conduct geospatial analysis by using python. If you don't have or don't plan to use ArcGIS, this book is not useful.