Good Book for beginners?

Because there are so many options in Linux based systems no book will give you the best core understanding of everything, so depending on what parts you want to learn the recommended books will differ. If you want to learn about the GUI operation we need to know what distro you are using, if you want to learn about network services it would be another book.

But since you asked about bash, then the listed book would definitely help you get a foundation, later on you can look for some books on advanced bash scripts and regular expressions.

There is a book that will teach you "basic" command line commands using bash. It is called " Essential Commands Linux Pocket Guide". It is small, easy to read and fun to use. I use all the time when I need to know a command to do some executions in the bash terminal. It is 179 pages, so not a lot to read, and it cost only $10. It also gives an introduction into programming with shell scripts if you want to write bash files. It is light and can easy fit in your pocket, which means it is designed to go on the road.

A very good feature of this book, it tells you where all the commands are located on disk. I highly recommend this book which you can buy at any Barns&Noble book store, for anybody getting started interacting with the CLI.

to Bash script:

http://www.ibreakyoufix.com/tools/books/Misc/2 Linux - Advanced Bash Shell Scripting Gude.pdf

where can we find this book?