VLC has an "export wizard" that will probably work. Choose mpeg-4 for everything if you don't know your DVD basics and author in Toast, or choose mpeg-2 if you do (if you can mux and author yourself, like with Sizzle or DVDSP).
If VLC doesn't work, you can demux ogms with the command line ogmtools, then work with what you get from there (usually avi and ogg vorbis).