I had been using Ubuntu rather than learning much about it for three years. I decided that I should get a proper understanding of the subject, and after much research and reading R.V. Cadea's review I bought this volume.
The book says that some knowledge of the subject is necessary to be able to understand it, this may be true, but the knowledge required isn't much. As an example the first chapters take you through the installation of the operating system from the supplied disc onto your machine.
I have read other books on Ubuntu, non has taught me so much so easily.