How to add a user to your Ubuntu system the GUI way
Adding new users to your Ubuntu install is a great way to get your friends and relatives into Linux. They’ll each be able to create a separate Ubuntu experience for themselves by customizing the look and feel of their desktops.
To add a new user, start by going to System-> Administration-> Users and Groups. This will bring up the user management windows. From here, click the New User button.
Next you’ll need to fill in some basic information about your new user, such as their user name, their real name and what kind of user they will be. Fiesty gives you three choices, Unprivileged, Desktop User and Administrator.