here is some fundamental document from apple.com, i find it really helpful

http://developer.apple.com/library/ios/navigation/

this link is a series of videos made by Stanford university about a course on Iphone programming, hope it would help

http://www.youtube.com/watch?v=xQzLHgls63E

And you can get the notes, assignments and sample files from the Stanford Winter 2010 class here:

http://www.stanford.edu/class/cs193p/cgi-bin/drupal/downloads-2010-winter

iphone sdk download

https://developer.apple.com/devcenter/ios/index.action

Here is a useful guide to creating your own iPhone app, from start to finish.  It has 11 steps, with 'programming' being only one of them.  Quite thorough.

http://www.smashingmagazine.com/2009/08/11/how-to-create-your-first-iphone-application/