I picked this book up for free from when my Computer Science Department moved to another building and they decided to clear out any unused books they didn't want. At the time I had barely scratched the surface of C/UNIX Systems and was just learning how to use Linux.
This book is perfect for any beginners starting out with UNIX, how the systems work, basic usage, and common commands. However, note that this book is quite dated but the commands and usage topics are still pretty nice to have in your toolkit when working with UNIX Systems. I would recommend this book to anyone interested in learning more on one's own. Note that having as Terminal nearby is a must whether is be a VM or a Native UNIX system.