as mentioned above, ICS(internet connection sharing) is a good and not too hard method to setup what u are looking for. keep in mind that ICS was introduced in WIN98SE(second edition). it will not work if you have JUST WIN98. the ICS wizard will make an .exe on the a: that you will have to run on computers that you want to share the internet from. read the help files and do some research before you play with it. ip's will be assigned by windows.
have fun playing with it.
bhat