How to add an user to the sudoers list ?

Steps for adding user to sudoers

• Login with root and use visudo (command to access and edit the list
  # visudo 
• Using the up/down arrows, navigate to the bottom of the sudoers file that is now displayed in the terminal.
  Go to just under the line that looks like the following :
  root ALL=(ALL) ALL 
• Add the following (replacing user with your actual username) :
  user ALL=(ALL) ALL 
• Now press Ctrl+X and press Y when promoted to save.

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