I would suggest these softwares in no particular order:
If you do not have the Video in Mpeg1/2 format prior to editing then you will require an encoding software. Then id suggest Tmpgenc for Mpeg1 and 2. CCE(Cinemacraft Encoder which is a bit pricey) for Mpeg2.
After you have edited and output the video in the proper format then the following softwares will make a great DVD again in no particular order:
Tmpg DVD Author.
Hope this helps.