In May 2010 I gave a presentation about Rigid Body Motion (ie the basics of rigid body physics and some general mechanics).
Here are two versions of my presentation (one with less text and one with more):
If you are interested in learning about rigid body physics, here are some books/links that I can recommend:
“Technische Mechanik 1 & 3” by Gross, Hauger, Schröder & Wall
“Mathematics for 3D Game Programming & Computer Graphics” by Eric Lengyel
“Physics for Game Developers” by David M. Bourg
“Game Physics” by David H. Eberly