If you are familiar with changing keyboard layouts on Gnome 2, it is very similar to how Gnome 3 changes the layout.
- If you're using Gnome 3 scroll down past the next two pictures.
- Find system and go to 'preferences', then navigate till you see 'keyboard'
- A window will appear. Just click the layouts tab then hit the 'add' button to add the different kind of layouts you want.
- Very similar to Gnome 2. First thing you'll want to do is click on Applications on the top left corner and go to System Tools
- Next click on settings inside System Tools and a window will appear. Click on Region & Languages and yet another window will appear.
- Click on the '+' symbol to add another language of your choosing. After you can close the window normally and you will see the drop down of your selections in the top right corner.
To toggle between input sources, you can use the keyboard shortcut : Windows + Space (next) or Shift + Windows + Space (prev) to go through your different keyboards. You should see the keyboard indicator in the top right.
NOTE: If the new language does not work after adding the layout, you may need to log out and back in, or reboot your computer