Hi there
Blender now has a well integrated great Rigid Body physics component
One of the basic factors for achieving realistically looking collisions,though,is to know when to use the various “Collision Shape” options available and (more importantly) why
This video is an introduction to the mesh colliders’ options available in Blender’s physics engine
Here’s the link to this tutorial :
http://www.youtube.com/watch?v=mrjIbp63zWc
Hope you’ll enjoy this!
Peter