This link should give you a good place to start. There are a few things to consider when trying to run Linux on an Amiga. First of all, many of the distrubutions are older and may not have drivers for all the "latest" AMIGA expansion cards (graphics, CPU, etc...) so be sure you read the docs before you decide on which flavor to try. I was using 2.1 until last year (I am slowly getting out of using my Amiga).
Regards,
Ltstanfo
