The best way to learn about almost any computer program is at your computer. Most people find that reading a book without using the program isn't very beneficial. Thus, the best way to learn Unix and is by using them. Use for everything you can. Experiment. Don't be afraid--it's possible to mess things up, but you can always reinstall. Keep backups and have fun!
For better or for worse, though, Unix isn't as intuitively obvious as some other operating systems. Thus, you will probably end up reading at least the first couple of chapters in this book.
The number one way to avoid using this book is to use the on-line documentation that's available. Learn how to use the man command--it's described in Section 4.2.