You probably want to check out the OpenZaurus
project then. I doubt that a general distro like DSL would be able to handle the hardware (or vice-versa) without lots of special modifications, so you should probably stick with what others have already been working on.
Unfortunately, there doesn't seem to be a lot of newbie-friendly info about the project or the distro at this time, so you'll still have to do a lot of research on your own. I recently bought a C3200 myself and I'm considering installing OZ on it, but I have to make sure it will still be able to handle a few things I need first, such as Japanese handwriting support. I'm not going to do it until I know it will suit my needs.
At least the wiki
seems to have good installation
instructions. The 3100/3200 versions are apparently designed to install to hard disk instead of ram though, which requires repartitioning the hard disk. It doesn't seem that hard to do, but it is a bit worrisome to have to mess with something so basic. Still, it looks like it's pretty good once you get everything installed.