Ubuntu is supposed to be really nice to use but I've not had a look at it yet.
http://www.ubuntulinux.org/If you want a small live Distribution try
damn small linux. Its 50mb big and runs from CD so no need to worry about formatting HDs
I'm very happy with the Fedora range so far. I'm still using 1 & 2 heavily but haven't had a look at 3 yet.
Kev
