[scandium]

So essentially you have, after sorting out the extraneous gibberish that is completely irrelevant/redundant from a hardware upgrade perspective:

Athlon XP 2600+
Via KT400A motherboard
1 GB DDR RAM
ATI 9600 AGP w/ 256 MB (XT?)
onboard AC '97 sound
60 GB Hard Drive
CD/DVDRW drive

Not much to work with. You have almost the same system I last had and sold (minus 1 hard drive) to scratch build my current PC, which is also due for a new build.

The motherboard is for the obsolete Athlon XP CPUs so that's useless to you and a 9600, even an XT, is too underpowered to justify buying an AGP motherboard since PCIe is the present and future... AGP is in its final death throes. No idea what your power supply is, but I doubt its anything higher than a 350W so you can probably toss that aside too... ditto the HD when you can get 250 GBs now for next to nothing, though based on the usage you don't seem to need a lot of space so if you want to save a bit you can hold off on a new one & just use the 60... ditto the burner since a DVD burner's a burner, I'd hang onto that too. The 1 GB of RAM is useful since DDR1 is all the S939 Atlhlon 3800 uses anyway.

Thus my advice would be a new S939 mb, cpu, PCIe video card, and power supply for now... if money's tight you can get a board with onboard video (as long as its ATI or Nvidia) and an empty PCIe slot to use for now and then add a video card later. Rest is mandantory. No specific recommendations right now, that's just my first reaction and I haven't been hardware shopping lately as I'm trying to hold off on my own upgrade until January (best time of the year to buy: best prices, sales, selection).