HowTo:Linux: Become Sudoer

Some linux distros like Debian won't let you use commands that modify file system so you have to add your account name at the appropriate file.
To do so:

• Open a terminal (Applications>Accessories>Terminal OR Ctrl+Alt+T)
• Run: 

                   sudo gedit /etc/sudoers

• Scroll down to the line root   ALL = (ALL)    ALL
• Add the folling line below the root line:

                    user   ALL = (ALL)    ALL
(replace "user" with the name of your account)