I think you may be confused.
Outputting your project as a DV-AVI can be one way of ensuring a smooth DVD burn, but it's by no means required. It depends on the kind of video you're using in your project, your project settings, your processor speed and RAM and your hard disc.
The VIDEO_TS folder is what you get when you select the option to burn your DVD files to a folder on your hard drive. It contains your DVD files: .vob files, .ifo files and maybe a .bup or two. When you burn these files to a disc, you copy this entire folder to a DVD.
I can't help you find this VIDEO_TS folder or the .avi that you output from your original. Have you used your computer's search tools?
>dismayed when I could not burn a DVD
What was the EXACT error message?
If the error was anything "like" drive not found, read these
Things and Software to AVOID when authoring/burning a DVD... says Encore, but also applies to Premiere Elements and disc burning
Start --> http://forums.adobe.com/thread/608660
#2 has WHY Explained http://forums.adobe.com/thread/607390
Also, some other reading that may help
Importing Video http://forums.adobe.com/thread/1065281
-and project settings http://forums.adobe.com/thread/1112086
Saving & Sharing http://forums.adobe.com/thread/1051093
Sharing for Computer http://forums.adobe.com/thread/1058237
Steve's Basic Training Tutorials... steps are the same for several versions