DistroWatch can help you figure out which distro you might want to try. Asking "what distro should I use?" around here is a bad idea, you are going to end up with suggestions to use every one of them under the sun. Might as well read some reviews and/or synopsis of the distros goal to help make the decision yourself. You'll probably end up using one of the major ones (Debian, RedHat, Slackware, etc.), but might as well take a look at some of the others.
Now as to some sites, here are some I have bookmarked.
LIke the one guy said. Someone will post the major distro.
Use slackware. here are some reasons:
1. If you can run slack, you can run anything
2. It will force you to gain the command line knowledge
3. Newer features are helping it to be easier for the newbs
4. Swaret (while supposedly good for other distros) is a great update tool
5. Its slack. That a good enough reason.