This is very "quick and dirty" using the CentOS gui tools as much as possible
-install server & open firewall to samba
-create office and supervisor groups and a /home/common folder
-create all users on server and make them part of office, (+supervisor)
-add all users to Samba with Windows names and passwords
-share all home drives and set user access on shares as appropriate
-set permissions in the directory at the root of each share, appropriate to users
-chmod g+w -R * #at the top level of each shared directory so groups can read and write