Uhm... iMovie+iDVD?

I know that's a lame answer but they came preinstalled on most machines at the time and I made several DVDs from variously sourced materials using that combination on PowerBook G4s. Just by drag the files into iMovie ('06, I think?, works with most things assuming you install the appropriate codecs), add some chapter marks, and iDVD away using one of the templates. For simple and braindead you could do worse.