I would suggest creating a separate sharing area, outside of the
user-profiles, perhaps C:\shared.

Under this, create the folders you want to share.

Then add the user-accounts of all your network-users to the server.

Create a couple of new user-groups for each level of access, and add the
appropriate users to each.

Share each of the folders, and under the share-permissions, remove
"Everyone" and replace it with the appropriate group.

If the accounts on the server have the same password as the accounts on the
workstations, the users won't be asked to authenticate twice.

You dont have to bother with groups, you can add the users directly to the
shares, but groups do make things easier to manage as requirements change.

To access the shares you could make them permanent mappings, or you could
use a batch-file to connect them at startup, of the form:

net use H: \\servername\openshare /persistent:no /yes
net use J: \\servername\restrictedshare /persistent:no /yes

which I find more reliable.

Hope this helps, Ian.