The first article in a new series I'm writing on administering Debian GNU/Linux has been published on O'Reilly Network: Installing Debian.
This opening piece is a little longer than typical for the series--installation is, after all, not easily digested into smaller chunks! Upcoming articles will deal with configuring the system for your desired use, and learning how to work with Debian's particular features and support systems.
Most of the articles will work well for Ubuntu and other systems derived from Debian. In fact, it's mostly in the details of installation that the experience varies most between the distributions.