I recently came a cross a very good system for education use.
which serves as a local shared library server for any education institution
its called RACHEL
its got instructions on building your own though its based on raspberry pi
In general I think it should be possible to use the same content here http://rachelfriends.org/
and the entire content visisble here http://rachelfriends.org/previews/rachelplus-en/
this might be probably for Nethserver on pi, but it could be great to have a way to build it into the general Nethserver.