Ask HN: Learning about iphone game development

I'm trying to learn some iphone/ipad game development but I'm not sure on where to start. What I want to do is being able to create simple 2d games, but I'd also like to learn more advanced stuff in the future.

I know that AI will be of an essential role in this industry but I'm wondering if there are any book/tutorials recommendations for developing games specifically for the iphone ecosystem.