I don't think Imgburn is authoring software, it burns files to optical disk but it can't create the DVD file structure (VIDEO_TS and AUDIO_TS folders). For that you need to look for something like DVDStyler or other freeware. They are basic and get the job done. The quality is based on the quality of the original file and the amount of compression you use to get it to fit a 4.3GB DVD. Once you've created your VIDEO_TS and AUDIO_TS folders, use Imgburn to burn the disk.
Note: the AUDIO_TS folder is always empty, it is just there because some older DVD players expect to see it.