speed, what else to look when purchasing a PC? If I decide to do some serious web programming, i.e., set up some web server, oracle, php server...?

MODEM, for internet connection

what kind of cd/dvd drives it has, how many usb ports(but you can always add those later), graphics card if you play games or watch dvds on it, sound card. Most people don't need a modem anymore, because people that buy new computers generally use broadband, so ethernet and wireless internet options are more important.

web programming is about the most benign thing you can do on a computer (although you may consider dual monitors), as for some of the other things, especially mySQL etc with large databases, ram is good - more is better. For web serving a pIII dual 1GHz box would work just fine, so just about anything you can find out there today will be satisfactory. Depending on the web-server configuration and the number of hits you're getting, multi threading will really pay off though, so look for dual core if you're hosting a really really popular site. Never worked with Oracle, so I can't speak to that one..When you're building a computer, if you want to minimize latency especially on first loads, you'll want a faster hard drive (say a raptor) 10k and 15k rpm drives have lower latencies and can stream data faster. Having more ram (depending on the os) will allow for more data to stay in ram, reducing the number of trips to the hard drive (your biggest data bottleneck on a modern pc).For just about any home use, your canned amd64 3500+, 1GB of ram, 7200 rpm 300GB hard drive, geforce 6600gt, 16x dvd drive, and 300-400watt power supply will work just fine.If you want cutting edge, amd64 X2 4400+, 2GB low latency (e.g. corsair xms or kingston hyperX) ram, 10k rpm raptors (or 15krpm scsi, but you'll have to get a card and possibly 80-60 pin converter), and a 7800GTX or X1800/1900.IMO unless you're doing predominantly video work, stay away from intel for now, they're too hot and for just about everything else, you'll get better performance out of an amd64.

Graphics card, sound card, What type of Cd drives it has, as for Ram go for the DDR RAM it's faster then the SDRAM,for your CPU gO FOR AN AMD processor there much better than the intels, mother board,etc. But it really just depends on what your buying the computer for