Adding users to sudoers file

Run a terminal session with your "root" account and execute the following:

echo 'loginname ALL=(ALL) ALL' >> /etc/sudoers

Where 'loginname' is your user account.
Use 'ALL=(ALL) NOPASSWD:ALL' if you don't want to be prompted a password.
If you are prompted for a password with 'sudo' it is the user password, not root.