adding new users in gentoo

[Nick Gawronski]

Hi, Following the handbook which does not work properly what command do I 
use to add a user on my gentoo system.  If I type useradd -m -g 
users,usb,cdrom -s /bin/bash it says invalid newmaric argument.  Also I am 
having an odd problem eth0 is detected as my firewire card and eth1 is my 
real network card.  How do I change the system to use eth1 rather then eth0?