1) Get a live CD like Knoppix, Mepis, PCLinuxOS, etc and use that to get semi comfortable with linux
2) Go to the Linux Documentation Project to read up on how to do stuff, also check out the RUTE user's guide.
3) Google for "Beginner linux command line" and "Beginner linux tutorial", there's lots of online tutorials to help you out.
4) Install a distro to the hard drive
5) Install some software from the distro's repository (pre packaged software)
6) Try installing something from source
7) Then try a more technical distro like slackware or gentoo
8) Finally, when you're really really comfortable, try Linux From Scratch.
Take the quizes in my signature to help pick a distro.