When sharing a Bib(la)TeX library, JabRef automatically recognizes a change in the bib file on disk and notifies the user of it. This works well on network drives.
Note: the use of a version control system (SVN, git, etc.) is recommended as this will allow for reverting changes.
To make the sharing of a Bib(la)TeX library easier, it is recommended to set specific library properties. In the menu Library → Library properties:
Select UTF-8 as encoding.
Define a General file directory, which will be used to store shared PDF (and other) files.
Check Refuse to save the library before external changes have been reviewed.
Define a sort order (year, author, title is recommended)..
Check Enable save formatters, and defines these actions, to help enforcing a consistent format for the entries.