Modem Sharing?

Can someone help me to configure the best way in setting up modem sharing on a Windows 2K server? I would like my Win98 clients to be able to dail out through the server to a local ISP. Do I need a modem sharing program? Do I need Proxy server installed? Or can Windows 2000 do it all? If so what client program do I install at the workstations?
Thanks.