Have you not yet installed a version of Linux. Ubuntu is a good starting point. But to learn you need to get your hands dirty, just reading the book will not teach everything you need. You can run Ubuntu just from a liveCD to see if it works on your computer.
Ubuntu is an African word meaning 'Humanity to others', or 'I am what I am because of who we all are'. The Ubuntu distribution brings the spirit of Ubuntu to the software world.
Also instructions for CD or USB
I bought one of the thick Ubuntu Unleashed books (6.06). But it is not for reading, but reference. I think I read the first couple of chapters and then jumped in and installed. My book now has tons of notes and pasted in pages of things that have changed. But I also now have a notebook of other printed pages and lots of reference material & notes on my PC.