I have searched this forum as well as the web, without luck, to find a detailed guide on how to set-up an Intranet on a linux server. I hope to be able to get some help from you folks.

Current network topology:
Approximately 15 computers connected to the internal network (majority is Windows XP, three Linux (2 Fedora 11 & 1 F12). We also have some visitors who can connect wireless)
Internet connection is ADSL, and the router assigns the IP addresses via DHCP.

We have a Linux Server (based upon Fedora 12) which serve a couple of tasks, i.e. a SAMBA repository, a CRM system and a CMS as well. These applications are accessable from all computers connected to the network. This is working very well, however there is a minor issue... Access to the server is done with IP numbers!

What I would like to accomplish is to configure an "true" Intranet, i.e. get rid of using IP addresses. Enabling all computers beeing able to access both the intranet and the internet.
So the simple question is; How do I do this? - I would love a step-by-step guide!