This thread should probobly be either in "Newbie" or "Distributions", but oh well.
For Newbie distros, look at Redhat, Mandrake, and Suse.
For "learning distros" (IMO), look at: Slackware, Debian, Gentoo.
Check out the reviews section for more help.
For learning linux commands and junk like that, once you pick a distro, go to the Links section of LQ.org.