server 2k setup

This is my first try at win2k server.
I first installed it, added a few users in computer management, then installed active directory and shared a few folders. I then also added users in computer management on a win2k and a winxp machine. Everything seemed to work but now I wanted start over and was wondering if I could uninstall active directory, or do I have to reinstall?

Anyways I reinstalled it and this time I want to just try a workgroup without active directory.

I installed users through computer management on all 3 machines(server2k, win2k, winxp) and shared a few folders on each.

I can see all on the network but when one of the workstations tries to open a shared folder on the server, access is denied or it says I don't have permission.

So where do I allow this on the server?

Are there any sites that describe how to setup server 2k and add users or do I just need to get the books?

Thanks,
George

To uninstall Active Directory run dcpromo from the Start->Run box

-You have to be sure that the users are the same at both server and the workstations; and theirs passwords (if they have them)
-Check the users permissions (access) in the shared folders. I will give them full access at first.