Calibre Content Server
Only the Source Library needs to run CCS,
A standard Web Browser is used at the user end to Retrieve Books.
The user simply enters the URL (or IP) and port of the host Calibre
eg. 192.168.0.17:8080 (for local LAN users).. Things get trickyier as router port forwarding is needed for outside access.
There are Copyright issues you must pay attention to. Public Domain and your own works are all that is permitted by laws. All else is considered 'aiding Piracy' (

note the Forum Rules on Members helping to do this )