about shell commands
 

hi all
i know that if i want to know how to use a command i can write
man command
for example to know the options of cd i write in the shell
but if i dont understand what it says what should i do?
is there any other documents that i can read in it more about what i want to understand?
or is there any docs that have some examples about the commands?
thanks in advance.

If the command, like cd, is non-destructive you can always experiment. As you learn what the options do, you will start to understand the descriptions in the man pages more and more.

There are also many, many books (both online and printed) available to help. Look for an introductory command line tutorial for your specific distribution. Failing that, a generic command line book.

The purpose of the man pages is to help you remember what the author assumes you already know...

Good books include "Bash Guide for Beginners", Machtelts Garrels---free at tldp.org
and "Linux in a Nutshell" pub.:O'Reilly---reasonable at any large bookstore.

There are various websites listing commands, but many of them simply parrot the man pages

This is very good:
http://rute.2038bug.com/index.html.gz
see also:
http://www.tldp.org/LDP/abs/html/index.html , http://www.faqs.org/docs/bashman/bashref.html#SEC_Top