I am yet to read the whole book but to be fair I have read till page 470 and still have another 450 or so pages to finish reading this book. My review will be based on what I read till page 470. This book will help you to learn unix plus it gives you historical perspective on it. It goes onto explain the history behind the use of the "return key" and why computers actually *do not* multitask. If that is not enough, there is a story (read funny) involved in explaining some of the things such as newline and return key. There are ton of other things that are explained in this book which involves humor and history.
This is my first unix book so I may be slightly biased but even then this book is worth for the history alone.
Overall, I found that if you know the history,it is easier to grasp and understand things rather than only reading them like facts. I will update after I finish reading this book.
I had to purchase this book for a college class, which sometimes ends up feeling like a waste of money since I don't get to research and choose my own book. That is not the case with this book. The author does a very good job of explaining and providing examples. I will be using this book as a reference for years to come.