That's not a very easy task, since the video card makers don't seem to provide a good way to read the screen display back into the PC fast enough. Usually I end up with jerking or slow video of a few frames per second. :(
A good tool to use that may work for you is CamStudio, and it's free. This allows you to set a region on the screen it will 'grab' pictures from and then put them into a standard AVI video file, hopefully fast enough for good video (a fast PC and smaller capture area make faster frame rates). This file you can then edit in the video editor of your pick. Still a lot of work and however long your video is, it will take at least three times that to get to the final version and then you get the joy of authoring the DVD to put it on. Typically it will take more. A lot more.
I think the most fool-proof way is to use a video card in the PC that also has a TV output. That way the screen can be recorded on a standard tape or DVD recorder. This makes for an extra step or two for any editing you might want to do., though. Not much way around that.
Fav quote - "Experience is whatcha don't get 'till ya don't need it no more."
System - Athlon 1.4GHz, Win98, Hauppauge PVR250 receiver and compressor.
Software -Magix Movie Edit Pro 10, Nero 6 + NeroVision Express, Moho 4.61, PSP 8.1, Bryce, Quicktime 6.52 pro, Goldwave 5, DVD-Lab.
Cameras - Panasonic GS9, Canon ES8400V, Canon EOS D20 and Canon A70