Quicktime (Animation codec) or AVI (Cinepak Codec by Radius, or Microsoft DV) is what I'd suggest - at the normal resolutions described above by Bruno021.

You're going to bring the finished animation into another program to convert the video to create a DVD (which will also create menus, etc.), so don't worry about formatting it "for" DVD when rendering the animaton.

Good luck - hope this helps-
-Lew ;-)