Hi,
You will need to have some sort of video capture device on your PC. Some graphics cards (Radeon All-In-Wonder, etc) have built in video inputs which would allow you to capture the video into a digital format on your hard drive. Be warned that you will require large amounts of disk space for this capture. If you don't have a video capture device you can always purchase a cheap TV capture card but the results are not great (Hauppage WinTV).If you are not going to edit any of the video then you could capture it directly into mpeg 2 format (this is the format DVD is in). If you wish to edit it then I would suggest you capture in DV format as this makes editing easier. Once you have the video on your hard drive you would then need some DVD authoring software to allow you to create a DVD. I use Adobe premier pro for all my editing and then burn the finished result to DVD using nero burning rom.
Hope this helps.
Mac