Multiple SSH users on Leopard?

Hi all, I'm playing around with using standard Mac OS X Leopard as a server. I've got everything running the way I want but now I'm trying to create user accounts and I've run into a problem. Currently, the only way I can allow ssh access to the server is by making a user an admin. Is there any other way to allow a user to ssh into the box without making them an admin? Also, should I be creating my users with the System Preferences panel or be using a command line like make user or something similar? Any help would be appreciated!