Don't bother with this if you want to use it for a raspberry PI model B+ (in my case). Its unreliable and causes it to freeze from time to time when any type of processing stress is placed on it e.g. media transcoding. After replacing this with a standard iphone charger and micro USB cable the issues went away.
I have read through the first 2 chapters of this book to get the baseline system set up and would say it is confusing to say the least. As one reader suggested there is a lot of "rambling" and not actually getting to the point. Not recommended.