Install sudo on Debian
In case you don’t have sudo installed already the installation is very simple as it is part of the official debian package repository: http://packages.qa.debian.org/s/sudo.html
Installation:
aptitude install sudo
Configuration files:
/etc/sudoers
Default configuration:
# /etc/sudoers
#
# This file MUST be edited with the 'visudo' command as root.
#
# See the man page for details on how to write a sudoers file.
#
Defaults env_reset
# Host alias specification
# User alias specification
# Cmnd alias specification
# User privilege specification
root ALL=(ALL) ALL
This covers the installation. You might want to check the sudo article on how you can use this.