The instructions would be included wither with your video card, or on the manufacturers site.
Couple of things you need to know...
Video technology used for video recorders is not the same as the technology used by webcams. Don't know if UK and US have different video standards.
Video to pc technology is typically either streaming - large masses of data or stills.
You would need two types of software..
- One to capture the video input, reduce the frame rate, and convert it to webcam format such as WebCamDV at http://www.orangemicro.com/webcamdv.html
- One to take the webcam formated images and display them on the web (google for "webcam software".
Don't know if connecting the two piecees of software can be done in real time.
Quite frankly, you're better off to buy a webcam. WeeCam is under $10 US. Creative labs has a good one that includes sound for around $30 US. Small price for saving a lot of aggravation.