Actually that guide isn't too bad. The information is quite good, but I'd like to make a few notes:
First of all, skip the first little blurb and go straight to the "Piecing it Together" section
Processor:The bits I'd change here are replacing the P4 with a Pentium D and the EE with the Core 2 Duo [smiley=thumbsup.gif] For the AMD, FX-60.
Memory: 1GB is about the current standard and not so much the 'preferred' level, but in about 6 months especially with the release of Vista, 1.5Gb or 2Gb might be the norm. (And get dual-channel if possible. BTW, what are some other really good forms/technologies for RAM?)
Video Card: Anything with 256MB on-board, 3D support. Recommended cards are the ATI x1600 Pro or nVidia 7900 GT. SLI is also good.
Hard Disk: 80-500GB or even more depending on what you're using it for. (If you're getting something above 300, consider RAID). Make sure it has SATAII or if you really want it, SCSI.
Sound: That part of the guide is alright to me. Sound technologies never have to be THAT awesome to fully enjoy your gaming experience.
Disc Drives: Looks ok too.
Monitor: Good too. 1000:1 is a pretty decent resolution for LCDs
The Rest: Good.
Hope this helps.