You need either a DV camcorder (digital camcorder) hooked up as a digital signal converter. I'm using this system - hooking my old analog Hi8 camcorder up to my newer mini DV camcorder which is then hooked up to my computer.
If the analog camcorder is all you have, you need to get an video capture card. Your camcorder will probably have three (or two depending on if it's stereo) RCA plugs that will go from your camera into the capture card (RED,WHITE - for audio and YELLOW for video).
You can find these capture cards either on the Internet, or at a place like Best Buy, CompUSA.... These capture cards simply convert the analog signal to digital so it can be used by your PC.