Well the specs of your new PC are plenty good enough to do video editing. More good news is that you alread have some very good editing software installed as Windows XP comes with Movie Maker. Get onto the MS web site and get the free upgrade to MM2 and you will be able to do all your capture & editing.
Although you have a DVD writer listed it does not mention any software that is used with it. You may well have some basic DVD authoring software provided, but if not I can recommend Ulead DVD Movie Factory 3. It is very simple to use and will add menus & chapters to your disk and then burn them for you. It can be bought online for around £25.
Do a search on these forums for details on useing Movie Maker. I know that some people have recommended a web site with full instruction on MM2:
http://www.eicsoftware.com/PapaJohn/MM2/MM2.html
Other than that about all you should need is a 6 pin to 4 pin firewire cable. Get this online for around £7, don't go into Dixons etc and pay around £20.
All my above recommendations are based on my assumption that you have a miniDV or other digital camcorder. If analogue then things really do start to get expensive and complicated.
Hope this helps,
Mark.