I would back the many here who said to get the Lynksys wireless router. I bought the router, two USB wireless adapters and a PCMCIA card for a laptop and in 30 minutes I had four computers hooked up through one cable modem. Two of the computers use Win 98, the laptop has ME and one computer has XP.
The only caveat I would add is Get the LATEST versions of all Linksys hardware. There IS a difference in both the hardware and its associated software, and the late stuff works great!
I'm currently running 4 computers hard wired into the Linksys Wireless Router, plus one desktop via wireless and one portable via wireless. Running WinXP, Win2000 and WinME.