The best way to learn about almost any computer program is by using
it. Most people find that reading a book without using the program
isn’t beneficial. The best way to learn about Unix and GNU/Linux is
by using them. Use GNU/Linux for everything you can. Feel free to
experiment!
Debian isn’t as intuitively obvious as some other operating systems.
You will probably end up reading at least the first few chapters of
this book. GNU/Linux’s power and complexity make it difficult to
approach at first, but far more rewarding in the long run.
The suggested way to learn is to read a little, and then play a
little. Keep playing until you’re comfortable with the concepts, and
then start skipping around in the book. You’ll find a variety of
topics are covered, some of which you might find interesting. After
a while, you should feel confident enough to start using commands
without knowing exactly what they do. This is a good thing.
Tip: If you ever mistakenly type a command or don’t know how to
exit a program, press CTRL-c (the Ctrl key and the lowercase
letter c pressed simultaneously). This will often stop the
program.