Transfering files to hard drive

[UCLA Bruins Fan]

Hi Everyone,
I spent a long time at my apple stores genius bar today trying to  
figure out how to transfer my tv shows in my Itunes library to an  
external hard drive (they explained that I could then take them in and  
out of my ipod from the external drive) The problem? None of us could  
figure out a way to do this using the keyboard with out a mouse.   
Selecting and copying them didn't work.  They did a pretty extensive  
online search for a keyboard shortcut which would let me do this, but  
to no avail.
Both they, and I, would love to know how this is done (if anyone can  
give me info on this they said I need to make another reservation and  
show them how it is done.)  So, can anyone help me out here?
The apple store people were great, but were as frustrated as I was  
that nothing we tried worked!
Any help you can give would be wonderful, so that I can free up some  
space on my internal drive!
Thanks, Olivia