[Alug] Hmmmmmmmm! Dial in Server

Hi All, Hope you all had a great Christmas. I am about to embark on a project and have no idea where to start! I want to setup a dial in server that allows users access to the Internet via our leased line. So I would imagine I will need a radius server as well as a proggy that answers the modems. Where do I start??? I have had a brief look at the linux-isp-redhat howto but i am not sure thats the setup for me... Any help would be great. TIA Michael Sage