I found some more links that may be useful if you looking for documentation or tutorials:

http://www.gnu.org/s/bash/manual/
http://www.perl.org/docs.html
http://www.php.net/

Collection of tutorials in JavaScript, PHP etc:
http://www.tizag.com/

Start with BASH, then move to python

Can recommend these for learning Bash:

http://tldp.org/LDP/abs/html/

http://tldp.org/LDP/Bash-Beginners-Guide/html/index.html

dwclarke wrote:

Can recommend these for learning Bash:

http://tldp.org/LDP/abs/html/

http://tldp.org/LDP/Bash-Beginners-Guide/html/index.html

ARGGG that's so full of mistakes!!!

Better check:

http://mywiki.wooledge.org/BashGuide

Learn PHP in 1 week, then also BASH.

PHP gives you extreme ease of use, than any other scripting language.

Although I come from core systems network protocol development background (that is C/C++), still recently after learning PHP, for all user-space app. extensions + other automations, I use PHP. I code bash scripts within PHP. So that is my suggestion.