Bibliography:

Chazelle, B. and Dobkin, D. P. (1987) Intersection of convex objects in two and three dimensions,
        Journal of the Association for Computing Machinery, 34.

LaMothe, Andre (1998) Windows Game Programming for Dummies,
        IDG Books Worldwide, Inc.  Foster City, CA.

Rokne, Jon (1992) An easy bounding circle, in Kirk, David (ed.) Graphics Gems III,
        AP Professional, Boston.

Links:

Computer Graphics FAQ
Algorithm to Compute the Intersection of Two Polygons .  This computes all points of intersection of the two
polygons as opposed simply testing whether or not they intersect.  Look to the bottom of the page for a link
to an applet which implements the algorithm.
Approximating Polyhedra with Spheres for Time-Critical Collision Detection
The Seattle Haptics Community
QuickCD