First thing to do is to stop looking at the size of the DV-AVI file. It
should be approximately 12gb per hour of video but that fact is totally
irrelevant.
When you re-encode the file and burn it to a DVD, you can fit an hour of
video easily on to a single layer 4.7gb DVD... and if you use LP,
approximately two hours.
MPEG1 is NOT DVD quality. It is VCD quality which is LOWER than the
standard VHS cassette tape.
Second thing to do is read the manual that comes with your third party DVD
burning program.
Third thing is to edit your movie in MovieMaker, and then save as a DV-AVI
file. Again, do NOT worry about the size of the file... the only reason you
would even need to consider this factor is when you check your hard drive
has enough free space to fit the file on it.
Fourth.. open your third party DVD burning software and import the DV-AVI
file. Tell it to make the DVD... which of course you now know how to do
because you've read the manual.
Sit back, let it re-encode and burn the DVD. Don't surf, play games, music
or do anything else while it's working. Step away from the PC and go do the
vacuuming, the laundry, make coffee, clean the bathroom, kitchen, bedroom...
whatever you like, just don't touch that PC until the DVD is finished
burning and (usually) ejects itself.