I know there are some tutorials for this with blueprints.
But the information is short on C++ side of things.
Tutorial on multiplayer fireing system.
Tutorial on adding Skeletal Mesh (weapon) to Player Mesh.
Tutorial on a instant fireing weapon and having server conclude its a ht or not.
Tutorial on delegates.
Tutorial on events.
Tutorials on states.
Tutorial on UE multiplayer game logic (a break down on how to use all the difrent classes).
Basicly more spesific tutorials targeted at one spesific thing.
As documentation is very general and it makes getting into UE 4 harder then it needs to be in my opinion.