Apple ipod

I really want to advance the development of the iPhone, where some good places to start learning?

Already downloaded SDK and get everything ready, I made Some applications of a single year limited helloworld tutorials, but I really want to be serious about this and I do not know where to get good lessons in iPhone dev. Any help are grateful to all the iPhone, developers, where he started? And thanks!

learn Objective C, and then go to apple.com and read tutorials and get to get SDK a mac buy books from Amazon iPhone

iPhone Game Development Tutorial 1 – Part 1