this can take 2+ hours, depending on your connection
watch the “getting started” videos
read the “Getting Started with iPhone OS” document, which links to:
iPhone OS Overview
provides a high-level introduction to iPhone OS and its technologies.
Tools for iPhone OS Development
provides an overview of the tools you use to create iPhone applications.
A Primer provides an introduction to the Objective-C programming language used for iPhone development. The document is targeted at existing C and C++ developers who want a simple introduction to the Objective-C language so that they can start writing code.
Creating an iPhone Application
gives you a guided tour through the code of the MoveMe sample application, which displays custom content and responds to user interactions with that content.