this is queit a old distro
use fedora 7 (redhat's latest version is called fedora)
the tool used if u have GUI GNOME working is "redhat-config-users" i think.infact rh website too have details.
if u want to know more about cmd u can try in terminal "man useradd"
ex usage in cli is like u need to specify ur primary group,secondary groups(wheel),home directory,user details passwd etc