First of all, no matter what, get Firewire. Do not in any circumstances settle for downloading video with USB. It's crap. Something like
this, and it will work just fine. I use a Creative Labs Audigy 2 for downloading my video (I have a TRV33), as it has a 1394 port on it. So that might be a good way to go if you could use a new good sound card as well....
Secondly, there is a lot of software out there to use, but if you are just entering the realm of video editing, get something that works and is simple to use, like Pinnacle Studio 9, or the *free* Microsoft video software. Check windows update for Version 2, as it's a lot better.
Third, make sure your computer has plenty of hard drive space for downloading AVI's, or your machine is fast enough to handle downloading to MPG (uses less space, but requires a faster hard drive and processing power to handle the on the fly encoding).
Tas.