Your desktop

About GNOME on Ubuntu — A list of notable modifications to the GNOME Desktop in Ubuntu.
Visual overview of GNOME — A visual overview of your desktop, the top bar, and the Activities overview.
Log out, power off or switch users — Learn how to leave your user account, by logging out, switching users, and so on.
Start applications — Launch apps from the Activities overview.
What is GNOME Classic? — Consider switching to GNOME Classic if you prefer a more traditional desktop experience.

Customize your desktop

Calendar appointments — Display your appointments in the calendar area at the top of the screen.
Notifications and the notification list — Messages drop down from the top of the screen telling you when certain events happen.
Pin your favorite apps to the dash — Add (or remove) frequently-used program icons on the dash.

Applications and windows

Startup Applications — Choose what applications to start when you log in.
Switch between windows — Press Super+Tab.
The lock screen — The decorative and functional lock screen conveys useful information.
Useful keyboard shortcuts — Get around the desktop using the keyboard.
What do the icons in the top bar mean? — Explains the meanings of the icons located on the right of the top bar.
Windows and workspaces — Move and organize your windows.