The Urban Penguin has lots of really useful playlists on his Youtube channel. They cover all the stuff you need to know about Linux/SysAdmin etc. I’ve not checked it out yet but there’s one playlist that has 70 videos to help you with LPI certification.
(LPI = Linux Professional Institute, by the way – www.lpi.org )
Note: The Urban Penguin dude is also an author of loads of Linux books, such as Mastering Lunix Shell Scripting.
While searching for the above, I just came across an online book for Shell Scripting that looks great too.