Login as admin and access the e-smith web interface from the menu selection. You will be using the Lynx browser to add users.
Note that you won't be able to get a shell login to the machine as any other user than root or admin for an out-of-the-box e-smith installation. Remember that e-smith is a _server_ installation, so you won't really be able to use it like a desktop install of a Linux dist.
Cheers,
Andrew