[LocoCoyote]

I have always found that the best way to learn something *nix in particular is to just play with it.
Use google to find helpful sites and use the man command (ie man ls ). One thing I love about *nix...there is tons of online documentation and most of it is already on your box!
I have to agree a bit with statica...try it first, do some research yoou will get more out of it that way!
Good Luck.