Its best to work with DV-AVI if you are going to make a high quality DVD.
It is a choice under 'other settings' when you save your movie from Movie
Maker.
However, just make sure you have a LOT of hard disk space, since the files
wll be
very large.  For example, I just did a 55 minute wedding video, and saved it
in DV-AVI and it was over 12 gigabyte...but wow, what a DVD!!  ha ha   I also
save the movie in 'high quality- ntsc'  (one of the choices also, in WMV) so
that I can watch it on my computer with Windows Media Player (a much smaller
size file) but still in high quality.   And then I can delete the large files
off my computer which I saved as DV-AVI......if I don't keep the original
footage on 'tape' then I will also burn the original raw footage to DVD just
in case I ever want to re-edit it into a future movie or something.  

You can note how you are saving your movie by looking at the 'settings
detail' in the lower left side of the 'movie setting' screen.    Look at the
various formats you can save in and note the 'quality' variations.   If you
save in DV-AVI it will be in 720 x 480 pixels.  You can read more if you go
into the 'help' file;  then 'index' and look up 'quality' to find the various
descriptions and definitions you can save in.   Good luck!