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.

Conventions

Before going on, it's important to be familiar with the typographical
conventions used in this book.

When you should simultaneously hold down multiple keys, a notation like
CTRL-a will be used. This means ``press the Ctrl key and press lowercase
letter a.'' Some keyboards have both Alt and Meta; most home computers
have only Alt, but the Alt key behaves like a Meta key. So if you have no
Meta key, try the Alt key instead.

Keys like Alt and Meta are called modifier keys because they change the
meaning of standard keys like the letter A. Sometimes you need to hold
down more than one modifier; for example, Meta-Ctrl-a means to
simultaneously press Meta, Ctrl, and lowercase a.

Some keys have a special notation - for example, Ret (Return/Enter), Del
(Delete or sometimes Backspace), Esc (Escape). These should be fairly
self-explanatory.