I've been wanting to dig deeper into the shell/terminal/bash for quite a while now and in my quest today, I found this great article that introduces the concept of the shell, the file system, permissions, etc. It's a great introduction for newbs like me and I'd imagine there are others who might be intimidated by the shell or can't decipher what some of the experience linux people type into those code boxes.
Link here: http://gd.tuwien.ac.at/linuxcommand.org/learning_the_shell.php
After that lesson, it continues onto shell scripting.
Link here: http://gd.tuwien.ac.at/linuxcommand.org/writing_shell_scripts.php
And then finally, I also found a great overview of .bashrc -- another incredibly useful file for anyone who plans to spend some time in the terminal window.
Take the time to read these if you don't know much about them -- it's incredibly insightful.