Upgrading from Ubuntu 8.10

To upgrade from Ubuntu 8.10 on a desktop system, press Alt+F2 and type in "update-manager -d" (without the quotes) into the command box. Update Manager should open up and tell you: New distribution release '9.04' is available. Click Upgrade and follow the on-screen instructions.

To upgrade from Ubuntu 8.10 on a server system: install the update-manager-core package if it is not already installed; edit /etc/update-manager/release-upgrades and set Prompt=normal; launch the upgrade tool with the command sudo do-release-upgrade; and follow the on-screen instructions.

Download

Get it while it's hot. ISOs and torrents are available at:

http://releases.ubuntu.com/releases/9.04/ (Ubuntu Desktop, Server, and Netbook Remix)
http://releases.ubuntu.com/releases/kubuntu/9.04/ (Kubuntu)
http://cdimage.ubuntu.com/releases/9.04/rc/ (Ubuntu MID)
http://cdimage.ubuntu.com/edubuntu/9.04/rc/ (Ubuntu Education Edition)
http://cdimage.ubuntu.com/xubuntu/releases/9.04/rc/ (Xubuntu)
http://cdimage.ubuntu.com/ubuntustudio/releases/9.04/rc/ (UbuntuStudio)
http://cdimage.ubuntu.com/mythbuntu/releases/9.04/rc/ (Mythbuntu)
http://cdimage.ubuntu.com/netboot/9.04/rc/ (Ubuntu ARM)