This "book" is very poorly written. I could get over the awful translation into English if the content was good, but honestly it reads as though it was written by a kid as a piece of school homework. There's no real structure to the content; it feels like one giant paragraph, written in less time than it takes to read the book, containing everything the author has concluded about Joomla after a friend told them about it.
Sorry if this sounds harsh. To try and be fair, there were a few little nuggets of interest, but only really in making me aware of a couple of features I'd missed and no actual detail about how to use them.
Multiple times the author suggests visiting their website for a more detailed description of a particular feature - so what's the point of the book then? Have I just paid for a list of features and corresponding website links?
In my opinion this book offers very little of use to someone trying to learn Joomla, even if you're a complete beginner don't bother with this. If it was free it wouldn't be worth the cost!