It depends on whether you have a desktop or a laptop.
Here are some options:
http://www.tigerdirect.com/applications/category/category_slc.asp?CatId=510&name=Firewire Adapters
Your local BestBuy should also have solutions on the rack/shelves.
Again, and I need to stress this, you're on some somewhat shaky ground, and I'm afraid I may have understated that to you. Firewire was/is an Apple standard because in those days, a Mac is where you went to do non-linear editing as the PC just wasn't strong enough to do it. For that reason, firewire was never really strong on the PC platform and never really became a
common port like it was on the Mac. The other strike you have against you is that Sony chose to implement their own version of IEEE 1394 Firewire in that camera called iLink, probably because of the early generation of that camera. From what I can read, it supposedly follows the standard so there shouldn't be any problems, but you never know until you try.
You're going to need Premiere Elements (You can download a FULLY FUNCTIONAL version at
www.adobe.com that's good for 30 days.), a firewire card/adapter, a firewire cable ($$$ if purchased locally), and a little bit of luck to get it all to work, but it should. Patience can pay off for the cable if you're willing to wait. They are spendy at places like BestBuy (as are ALL cabling at BB because that's where they make their money!) but if you're willing to wait a few days and order one, they are dirt cheap at places like
www.monoprice.com .
The good news is that it is still agreed in my industry (security, networking, and computer systems control) that tape is STILL the best long-term archive media. It has proven itself over time. The problem is that your camera has NOT, and finding mini DV cameras in the future (already really) is just going to get harder and harder, especially if something happens to your camera, so you really need to at least get it over in a standard file format (as you have already realized). While mini DV is a standard, the implementations are not. Sonys won't play Canon tapes and so on and so on. Some older Sonys won't play newer Sony tapes either. What I'm trying to stress is that even though you already have it on a pretty reliable medium, you don't have a sure-fire way to know you can play them in 10 years and you certainly don't have a way to copy tape-to-tape to backup the singles you have now anyway. Drives eat tapes and we all know that, and the mini DV wrap sequence is very complicated. It has many potential points of failure just by its very design.
You're on the right track and headed the right way. Let us know what you do as a next step.