O’Reilly author Wei-Meng Lee has published a short free PDF that will get you started building iPhone applications with Apple’s SDK:
If you have always wanted to learn iPhone development but don’t know how to get started, download my free eDoc on Getting Started with iPhone Development. Try it out and see how easy it is to get started!
Developer Learning Solutions: Free eDoc on Getting Started with iPhone Development
If you want to build apps with the unofficial SDK, check out the iphone-dev Google Code page. Jonathan Zdziarski’s iPhone Open Application Development covers the SDK and how to build applications with it.
