Ubuntu is...

Ubuntu is a community developed, Linux-based operating system that is perfect for laptops, desktops and servers. It contains all the applications you need - a web browser, presentation, document and spreadsheet software, instant messaging and much more.

The Ubuntu promise....

• Ubuntu will always be free of charge, including enterprise releases and security updates.
• Ubuntu comes with full commercial support from Canonical and hundreds of companies around the world.
• Ubuntu includes the very best translations and accessibility infrastructure that the free software community has to offer.
• Ubuntu CDs contain only free software applications; we encourage you to use free and open source software, improve it and pass it on.  

Guides....

Find here a selection of guides to help customise your Ubuntu Server. It will start with a basic install of the new 8.10 server edition of ubuntu (click here for their website).

Guides for Exim with mysql, dovecot, spamassassin (inc spamlearn cron) and clamav are included.  Just like the freebsd guide i'll try and include all the info that helped me, explaining all the fixes i used and the websites i found them on.

Also included is a full guide for swapping from a single harddrive to 2 new drives in RAID1.