Docky is an advanced shortcut bar that sits at the bottom, top, and/or sides of your screen. It provides easy access to some of the files, folders, and applications on your computer, displays which applications are currently running, holds windows in their minimized state, and more. Some of Docky’s amazing features include themes, plugins, 4 different hiding modes, advanced indicators, zeitgeist integration, and window management.
To Install Docky open your Ubuntu Software Center (Applications -> Ubuntu Software Center) and search for docky. Select the search result and click on the Install button. Fill in your password and wait while Docky is being installed. When install you can find Docky under Applications -> Accessories -> Docky.
Visit Docky wiki page.