Here's what I've found:

– Learn Objective-C: http://cocoadevcentral.com/d/learn_objectivec/

– iPhone Dev Central Tutorials: http://www.iphonedevcentral.org/viewtutorials.php?page=Tutor...

– iPhone Application Programming Guide (login required): https://developer.apple.com/iphone/library/documentation/iPh...

Best resources - the sample apps on Apple's iPhone Dev site (you need to be registered (free))

There's wide selection. Find one that you like, and play with it. Change things, add things. Turn it into something else.

Worked for me. YMMV

O'reilly Safari Library costs money but you get unlimited access to many current programming books to read online. There are several books available on iPhone development and Objective C programming. It helped me immensely when learning Javascript. Also, you can often search for functions and text within the books using the website. Going back and forth from a paper book to the monitor is not as efficient for me; so it worked great, in my case, to switch virtual desktops and browser tabs while working out ideas and learning about syntax and functions.

Code, from what is understand, is written in Objective C which is a superset of C. So take a look at some online tutorials regarding Objective C. Syntacticly, it looks different than other popular languages ( to me ).

Stanford iPhone Application Programming course materials here:

http://www.stanford.edu/class/cs193p/cgi-bin/index.php