I have set up a server and a network and I have joined my computers to my network. What I want to do is put many users onto the network. So that many different users would be able to log onto the machines and use them. I can add them individually through workgroup manager but is there not an easier way? I have a text file containing the names of my users and their short names, I can add other information if it is needed but would like all users to have a default password to start with and then they can change it.
Is there a way to import user information into the server?

You can import users from a file using Workgroup Manager
Here is a link to the Mac OS X Server Server Administration
For Version 10.5 Leopard Second Edition. This covers the Workgroup Manager.