Distro suggestions are many. Just about one for every user. I've tried RH, Mandrake, Debian, Slackware... I find Slackware to be easy to install and maintain. The pkgtool which is used to install/uninstall Slackware packages (.TGZ) is very easy to use.
If you want a computer with a nice desktop, I would suggest installing the X-Windows system, and using FluxBox as a window manager. Some time ago I installed Slackware 8.0 or 8.1, I don't really remember, and FluxBox on a Pentium 133MHz with 32MB RAM. The windowing and browsing was very acceptable for being such an old computer. FluxBox is very configurable.
This is just my personal opinion, and if you're not sure, I would encourage you to test a few distros to see which one you are most comfortable with.