[1]If you'd like to add new user, Add like follows.
# add a new user "ubuntu"
xerus@dlp:~$ sudo adduser ubuntu
[sudo] password for xerus:# own password
Adding user `ubuntu' ...
Adding new group `ubuntu' (1001) ...
Adding new user `ubuntu' (1001) with group `ubuntu' ...
Creating home directory `/home/ubuntu' ...
Copying files from `/etc/skel' ...
Enter new UNIX password:# set password for new user
Retype new UNIX password:# confirm
passwd: password updated successfully
Changing the user information for ubuntu
Enter the new value, or press ENTER for the default
Full Name []:# if not need, Enter with empt
Room Number []:
Work Phone []:
Home Phone []:
Other []:
Is the information correct? [Y/n] y
xerus@dlp:~$
[2] If you'd like to give privileges to a new user, Do like follows.
xerus@dlp:~$ sudo usermod -G sudo ubuntu
xerus@dlp:~$ su - ubuntu
Password:
# try to execute a command which requires privilege
ubuntu@dlp:~$ sudo reboot
[sudo] password for ubuntu: # password for 'ubuntu'
Broadcast message from xerus@dlp
(/dev/pts/0) at 19:59 ...
The system is going down for reboot NOW!
