Howtoforge posted a guide about setting up Ubuntu 8.04 LTS as server

This tutorial shows how to set up an Ubuntu Hardy Heron (Ubuntu 8.04 LTS) server that offers all services needed by ISPs and hosters: Apache web server (SSL-capable) with PHP and Ruby, Postfix mail server with SMTP-AUTH and TLS, BIND DNS server, Proftpd FTP server, MySQL server, Courier POP3/IMAP, Quota, Firewall, etc.

The Perfect Server - Ubuntu Hardy Heron (Ubuntu 8.04 LTS Server)