I have just researched this same issue for myself. The answer depends on what level you want to go to.(posted 9219 days ago)The first thing is to get a mini tower rather than a flat desktop unit so there will be room for all the cards with adequate ventilation.
The second is to get at least 128 MB RAM and a fast hard drive that is as big as you can afford. The cards and software keep getting more demanding so you should get at least a Pentium II (which should get cheaper because they are releasing Pentium III now).
The third question is what operating system? If you get a MAC, this isn't an issue, but if you are buying a PC, you will have to choose between Windows 98 and Windows NT. Some higher-end editing programs require NT. If you are planning to stick with a consumer-level card and program (one of those under $1,000 bundles) you can use Windows 98 -- although some programs are still only Windows 95 compatible I am sure this will rapidly change. Cards at this range require the camera as a deck and playback device. If you get a MAC the Radius Moto DV/Edit DV looked good to me. If a PC, they will be releasing a PC version somewhere down the road. They currently bundle their card with Premiere 5.1.
If you want to edit anything longer than a music video you will ultimately need external AV drives which will require a SCSI controller card. This is something you can add when you can afford it(that's why you'll need a tower).
But if you want to really read all about it, there are a couple of good places to go:
videoguys.com - their web site gives specs for a system and makes some specific recommendations. They sell card and software bundles when you are ready for that purchase. It's a good place to see what's on the market and has links to all the manufacturing sites.
editing software - all the manufacturers link to reviews praising their product.