Firstly; I don't know any real sources, but try looking in gamedev.net

Secondly; Haven't attempted, but I have to soon. Not soon enough to claim of trying.

Thirdly;

First person- I'd add lower part of the body (possibly all the way to the shoulders below the 'eyes' so I can simulate damages and give more "dynamic" feel by forcing the slow head movement and Sony's RTWS (Real Time Weapon Swapping) with animations. As for them (animations) I'd use bones that react impact.

Third person - Bones that react to dynamics, RTWS, Move the head and body when changing the camera's orientation and add slight darken to the areas the player isn't supposed to see (just darken, not full black, that'd be annoying)