Librarians in Center EX are like their physical counterparts in actual libraries. They have full control over the entire library. You should have at least one librarian, but probably not more than a handful. Too many librarians can quickly cause chaos, as they place documents and folders anywhere without communication with other librarians.
In order to prevent this chaos, it is best to start out with one librarian who is responsible for the over all tree structure of the library. That librarian then adds folders to other staff members, and gives them full control folder permissions on that folder. This way, these staff members are responsible for their section of the library, but cannot alter anyone else's folders.
For example, the one librarian can add a folder per region, per center, or per special program, or some combination of these. Then the appropriate staff members are assigned permission by that librarian, effectively making those staff members 'librarians' of their own folders.
A librarian can even grant access to a staff member to only create internal documents in a folder, as public documents requires a higher level permission. This is because anything put in front of the public deserves a little more scrutiny and perhaps that control should only be given to certain staff members.
