The book suggests good design tactics, explains the basics of flow control with the if command, and demonstrates use of the exit status.
The book continues through string expressions, the use of [] and (()), the logic of && and ||, reading keyboard input, looping with while, until, and for. The book offers good advice for troubleshooting, shows readers how to create effective case statements and make use of positional parameters. It contrasts the manipulation of strings and numbers.
Chapter 35 covers arrays with examples that are both clear and extremely useful for building, assigning values to, accessing, sorting and deleting arrays.
The book ends with Chapter 36. Entitled "exotica", this chapter covers topics such as grouping commands within braces and parentheses, subshells, traps and named pipes. As you can see, readers have moved into fairly advanced material by the time the book ends.
The Linux Command Line provides a very logical progression of topics with just the right mix of example and explanation at each level. Each topic builds on the previous material without ever slapping the student upside the head with "here's a pile of commands you need to swallow". Anyone who reads this book and makes use of the examples provided will not be able to avoid becoming a Unix command line pro by the time they've hit the end of the book. It provides an excellent introduction to the command line that takes students from knowing nearly nothing to using impressively sophisticated commands. And for anyone who learned Unix by being tossed into it and figuring things out a little at a time, it might even fill some important holes that leave them saying "Oh, I get it now!".
The Linux Command Line is easily the best introduction to Unix or Linux that I have come across to date.