How to add a user to the sudoer list:

1. Open a Root Terminal (you need to be root first time ) and type visudo (to access and edit the list)
2. Using the up/down arrows, navigate to the bottom of the sudoers file that is now displayed in the terminal
3. Just under the line that looks like the following:

root ALL=(ALL) ALL

4. Add the following (replacing user with your actual username):

user ALL=(ALL) ALL

5. Now press Ctrl+X and press Y when promted to save

That's it, your new user now has root privileges!