AppleShare has two important sets of configuration information. The first is the Users and Groups data file, which is stored in the Preferences Folder of the system folder.
The second is folder permission information. On read and write volumes, this information is in an invisible file at the top level of the volume called "AppleShare PDS." On read only volumes, the information is stored inside "System Folder:Preferences:File Server." There is a PDF file for every volume that has been mounted while AppleShare was on.
You should back up both the Users and Groups data file, and the File Sharing folder as well.