Ubuntu/Linux related useful websites

http://www.ubuntu.com—The place to start when looking for news, information, and documentation about installing, configuring, and using Ubuntu.

http://distrowatch.com/ - All about tracking linux distros.

http://www.gnu.org/software/grub/—Home page for the GRUB boot loader.

http://www.x.org/—The X.Org Foundation, home of X11R7.

http://www.linuxquestions.org/—The Linux Questions site, a useful set of community forums that can help you find answers to your more frustrating problems.

http://www.gnome.org/—The launch point for more information about GNOME,
links to new clients, and GNOME development projects.

http://www.compiz.org/—The official page for the Compiz project, including Compiz Fusion, a set of plugins for the Compiz window manager.

http://www.xfce.org/—The official home page for the XFce project.

http://www.kde.org/—The place to get started when learning about KDE and the latest developments.

http://www.codeweavers.com—Home of the popular crossover office; required if you want to try to run Photoshop under Linux.

http://www.gimp.org—Home page of The GIMP (Gnu Image Manipulation Program).