ICS is pretty easy - there should be plenty of documentation in Windows Help. You just need your primary computer (the one connected to comcast) to have two network cards (i think), then the ICS wizard will let you make a floppy disk that'll do all the configuration on your other machines.
Even better IMO is sticking a hardware router between you and the cable modem. You can get them for under $100, and it'll let you hook up plenty of computers. Of course, you have to be willing to spend the $$, but given the extra security it gives you, I'd say it's worth it.
buy.com has a whole list of the things.
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q234815 is a good place to start for more info on ICS.
Hope this helps.