I want to mention another book, called Core Techniques and Algorithms in Game Programming. It has a very high level explanation of various AI techniques(and scripting, path finding, and other related things) along with pseudo-code. The way he explains it in this book makes it seem very easy to understand.
+1 For Mat Buckland's book that Austin J suggested.
Really excellent book. Was able to make a reasonably sensible set of bots for a top-down 2D game using Reynold's Behaviours, A* pathfinding and finite state machines.