A great screen cast/pod cast by Dann S Washko linux in the shell.
From his own website:
Linux In The Shell aims to explore the use of many commands a user can run in the Bash Shell. Tutorials include a write up with examples, an audio component about the write up, and a video component to demonstrate the usage of the command.
I have found his tutorials and explenations immensly helpfull in learning to use the bash shell more effectively from the basics to some of the more esoteric.
His website can be found at: