The How-To Geek has a tutorial on upgrading from Ubuntu 6.10 to 7.04. It's not really something that needs a tutorial, but you can always show it to your friends to prove how easy Linux has become. The only thing that's not obvious is that you need to run update-manager with a "-c" parameter (which means "check if a new distribution release is available"). Other that that, it's as simple as clicking "next" a few times.

Minor things to note:

  • if user has modified some configuration files in /etc, he/she might be asked if he wants to keep them unchanged or overwrite them with a new version. I always backup the entire /etc, replace conf files if asked and then look for anything that I've changed before. Then I put those changes to new config files.
  • TFA writes about new shiny Control Center in Ubuntu. AFAIR devs decided not to go with it as default (don't quote me on that) and leave old "Preferences" and "Administration" drop-downs. At least that's how it looks like on my desktop. To run the Control Center, run gnome-control-center from the command line.