Stanford University recently published their starter course on “How to develop and iPhone application”. This was only possible because Apple finally loosened the restictrions in the iPhone SDK NDA which every developer has to agree when downloading the SDK.
So for anyone, with less to none knowledge in iPhone Development or Objective-C, XCODE etc. this course is a great thing to get started with.
The course material contains instructions, slide and code samples in Obj-C.
Best thing is to start from the beginning and finish all assignments/projects as proposed in the lecture.
An Overview of the material is available here: http://www.stanford.edu/class/cs193p/cgi-bin/index.php