This is a great beginning resource that takes a look at all aspects of path finding in a very easy to digest approach.

Amit’s Notes about Path-Finding

... Pathfinding addresses the problem of finding a good path from the starting point to the goal―avoiding obstacles, avoiding enemies, and minimizing costs (fuel, time, distance, equipment, money, etc.). Movement addresses the problem of taking a path and moving along it. It’s possible to spend your efforts on only one of these. At one extreme, a sophisticated pathfinder coupled with a trivial movement algorithm ...