hi there Synesthesia,
you should give TOVID a try.
It's basically a set of ready-to-go scripts that make it much easier to "convert" any .avi, .mpeg, ...media file into a DVD-ready format which then you will also be able to burn on a DVD considering you have all the dependencies it requires.
You're better off just going to
http://tovid.org/
and read through the DOCS and FAQS before you try it out - also make sure that you try to set up all dependencies (such as Python, wxPython, mplayer, mjpegtools, ffmpeg, ImageMagick, SoX, dvdauthor, vcdimager, transcode,
libdvdcss, lsdvd) prior of attempting to install tovid to ensure you'll get the maximum features!
I'm using it and loving it and I'm sure you will too once it's set up correctly!
Have fun