Setting up a UK keyboard layout

On ubuntu fresh install:

Login and press Ctrl-Alt-T to open a Terminal and run:

setxkbmap -layout gb  

To get UK keyboard with double-quotes on Shift-2 and @ sign on RHS.

Go to Keyboard layouts under system settings, and click on it. Once open remove English (US), and add the English (UK) that you want. Click on the Plus (+) sign to add, and the minus(-) sign to remove. See images below.

(It will be English UK with Extended Win Keys)

Aware that using the GUI is very beginner esque, but I need to be able to type before I can get to grips with Ubuntu!

Click on settings, keyboard, and then, in the bottom left, Layout Settings. On the left there is a panel that displays currently installed keyboard layouts. By default, only English (US) is available. Below the panel, click the + icon and select English (UK). This will add English (UK) to the panel. Use the ^ symbol to bump English (UK) above English (US). The panel is hierarchical, so now English (UK) takes the priority.

You can even select English (US) and use the - to delete the keyboard from the panel.