Having trouble with a New G4 and installing Yellow Dog from CD

[Martin Akerman]

Please, somebody help me get this resolved.
I'm not exactly a Mac Wiz but I am a huge fan of linux.
Got the mac because it was the most reliable hardware I could find.
I need to know what I need to disable or get by in order for yaboot to 
take control during startup.
The CD does not boot at all.. goes straight to OSX.
Machine is 1GHZ G4.  Jan 2003