Launch the iDVD application (you may need to find it in your Applications file). Choose "Create a New Project" and save your project. The name you give it will show up on the DVD when inserted into the computer to be played.
The default theme will play, but ignore it. Switch to "DVD map" view (either by clicking the button below the iDVD screen or by choosing "View" from the menu bar at the top and selecting "Show Map"). Drag your final QuickTime .mov file to the little box that says "Drag content here ..." You should see an icon for your file in the box and it should begin encoding. To see the encoding process, choose "Project" from the menu bar and click on "Project Info."
Before you burn your DVD, choose "Advanced" from the menu bar, and click "Loop." You will see a small circular arrow appear in the box on the DVD map w/your file. This will ensure that you bypass the funky little theme that iDVD so desperately wants to play -- and your movie will automatically play w/out a theme when you put it into the DVD player.
Now, you click the "Burn" button, or choose "File" and click "Burn DVD." Insert a blank DVD when the program tells you to. I recommend DVD -R (though +R will also work in these Macs. I just have had better luck w/the -Rs). It should take about 20 min to burn, hopefully less. When the first DVD is done and you eject it, the program will ask if you want to burn a second one. Go for it.
Good luck and see you Wed w/your finished DVDs in hand!!!!