I'm new to dvd creation, but I think that you make a file from a video file, and that is called the dvd image, which is then put on the dvd. It's different than something like a cd where you can just throw stuff on it and it works. As to the quality issue, I think it depends on what you're uploading the dv with. If you can get the dv tape into mpeg2 or avi, those are usually higher quality in my very limited experiance.
Someone correct me if I'm wrong, which is very possible ...
\"He\'s not as tough as he thinks he is!
Neither are we.\" - The Sting