If you're interested in this kind of thing and want a gentle introduction, I highly recommend CodeCombat [1], which offers both a single player version for learning the system and a multiplayer version for writing AI code. [1] http://codecombat.com
Can you recommend other resources and reading materials other than this? I would like more on top of the provided links thank you. OP's url have got me interested in AI now, but mainly for solving puzzles like this.
Programming Game AI by Example http://www.ai-junkie.com/books/toc_pgaibe.html