Go to '<http://www.xlr8yourmac.com/systems/iMac_g4/imacg4_takeapart.html>' for step by step instructions.
I have a DVR-106 in my dual 500 MHz G4 PPC PM and it works fine with Jaguar [10.2.8], Panther [10.3.4, 10.3.9], and Tiger [10.4.0], including Apple's 'i' products that can burn discs.
If you have not yet purchased the DVR-106D, you may want to consider the DVR-109. If so, you may want to download 'PatchBurn' ['<http://www.patchburn.de/>'], just in case it is needed - by your MacOS X.