Create a new user

adrian@openindiana-tuts:~$ useradd $USERNAME #where username is the name of the user.

so e.g.

adrian@openindiana-tuts:~$ useradd veek
adrian@openindiana-tuts:~$ passwd veek #to set a password for the user.

and you're most of the way there, now refer to making a new home directory for a new user