Linux for PowerMacs and their clones. The Linux ftp archive at the University of North Carolina . You should use a mirror if one is available. Trust me, it will make life easier. If too many people are connected to a single ftp site at once, performance will really suffer.
Mirrors are almost always less crowded.
The list of mirrors can be found here or in HTML format here . The web site of the Debian distribution of Linux. Debian is a non-profit group that makes Linux available for free over the Internet. This is a very high quality distribution, with a great package dependecies system that keeps track of what software you have installed. This makes adding and upgrading software far easier than with any other distribution.