If you just want to learn Linux the easy way, without seriously screwing up your computer, go to www.floppix.com
! They have a Linux distro on two floppies, made especially for newbies! It doesn't allow any harddrive interaction, so you can't mess anything up. The website also has a "Labs" tab at the top, which will teach you all the basics of command line Linux. I'm sorry if somebody already posted this, but I just did a search, came acroos this, read the first post, and instantly put in a reply. Sorry for any repeat suggestions.