using a windows 98 pc and a xp pc together can be kinda annoying sometimes... the best way to do it is what ean said, connecting one computer to the internet and having the other use "internet connection sharing" via the i wish to connect my computer to a lan section of the internet wizard.
however if you going to do things this way then be aware... i have been caught out by this before, some network wires will not let you connect two pc's together for some unknown strange and very annoying reason... so it best to ask an assistant which cables will allow this...
or there is an alternative, which i use and is still cheaper tha buying a router...
i will go through the two ways of doing things...
1: HUB
to connect a hub to your computer is easy, a hub is basically a very small server, and can deal with patching packets (an expression of data sending to the various computers on the internet). a hub is powered with a transformer, and connects all computers up via network cables... you can get hubs in either 10's or 10/100's (the latter is better). they are very easy to set up, and computers are detected almost immediately... this is the method i use and have found it very usefull... and cheaper than a router
2. ROUTER
routers are small hub-like mini servers, that send and recieve packets of data in 10/100 speeds. much like a hub, although there is a difference, a router has the phone line jacked straight into it, and usually has a built in hardware firewall... very usefull point about routers, and the most cost effective way to firewall your pc (if the router doesnt say "hardware firewall" on the box, maybe you shouldnt buy it, but in some cases you can install a firewall free of charge into the firmware). the downside on these is they are sometimes death himself to setup, and the price isnt right!
on both instanses you need a PCI 10/100 network card... which are damn simple to install... and windows 2k and XP usuall find and install them quickly, with the windows driver database. unless you already have a network card prebuilt into the motherboard (look on the back of your pc, if you see a phone line shaped plug in the back then you already have a network card.
caff.