If you want to also transfer VHS or other analogue video to your computer you need to look at Rescue Your Video Tapes as the simplest and cheapest software for doing this. It includes a video grabber.
If you already have a video grabber and have the correct drivers for it (to suit your OS) and for more advanced editing and for a program that includes the facility to transfer analogue video to your computer and later export to various formats, including DVD, you should look at Movie Edit Pro at least.