I had a difficult time finding a CPU mining software for Linux that actually would compile and run... most seemed to require a GPU, even if I'd only be using the CPU mining capability. cpuminer, by jgarzik, was a snap though.
I detailed the (simple) instructions at
Pooled CPU Mining for Bitcoins on Ubuntu.
I tested it on Ubuntu 11.04 and 8.04.
My other Bitcoin-related posts:
Bitcoin posts on doctormojo.com, although there's nothing really to brag about yet.
Mojo