I cant speak for Perl but when it comes to bash/shell scripting, I've got a few links for you :)

First have look at the Linux Document Project (http://www.tldp.org/guides.html), the Bash Guides are really good, thats how I first got started. Also, for bash once you've gone through the guides, download the source (apt-get source bash if your own a debian based distro) and checkout the test suite, this will give you a good look at the internals.

Also be sure to memorize the ins and outs of the the man command :)

Best of luck