You need a firewire card and an editing program.
Some motherboards come std with a firewire card built in others you just fit them easy.
Usually some basic software comes with it to get you going.
You need plenty of memory, big ram, and hopefully atleast a P4 2ghz processor or you'll bog your system.
when you first instal and set up the firewire card have your camera plugged in and switched on, the system and program will detect the camera and auto configure.
If output from your camera is AVI or DVD it takes about 1gig of memory for every 10mins of vid. Then you edit that down, add titles, effects etc but the raw work file is way larger than the finished product.
When the vid is finished you save it in a variety of formats. WMV is around 5MB per minute, MPEG1 is 10MB per minute, MEG2 is around 100MB per min and so on. So you can see why when I put them on the net I use WMV, but if I were burning a disc for home use I would use AVI or DVD.
I bought a firewire card for $40 and it came with Ulead 7.0 to start with, good enough unless you get hooked in for more effects.
Hope this helped you out, pretty easy really.