What advice can you give on building a decent gaming computer?

I have an alright computer currently, but I would like to upgrade some of the hardware and such so that I can have a decent gaming computer. I looked up some of the information that my computer has and hopefully it is enough to answer my question. I have Microsoft Windows XP Professional, AMD-K7 Processor (499 MHz), 320 MB of RAM, ACPI, 3dfx Voodoo3 display driver, HL-DT-ST CD-RW GCE-8160B (CD Drive), Samsung DVD-ROM SD-612B, and a 3Com EtherLink XL 10/100 PCI TX NIC, and a Texas Instruments OHCI Complaint IEEE 1394 Bus Host. Any help as to what to upgrade and what to upgrade to would be great. Thanks!What advice can you give on building a decent gaming computer?
Wow thats not descent at all. I recomend buying a totally new computer with 2gb of ram, an 8800 video card, and at least a 2ghz cpu