Best Way To Learn iPhone Programming
I'm a 20-year-old college student who's been programming for a long time in PHP (I know...I know. Sorry.) and most recently Python.
Of course, check out http://developer.apple.com/ios. Their documentation is incredible. They have "Getting Started" guides, learning Objective-C, Cocoa touch, and building basic apps, all the way up to using specific classes. It's definitely a fantastic resource.
The Stanford classes are excellent as well.
But really, once you've gone through those resources (and really, while you're still going through them), you really need to just sit down and build something. You've hopefully got some kind of app in mind. Just start building it. If you find it's too complicated for your skillset, scale it back. Even if you just make your app present a UI and maybe a Settings screen, you'll have accomplished a ton, and taking that and making a full "regular app" is at mostly the same skill level (and confidence level).
I've struggled through other iOS dev books and, for me, this one has been the most clear.
I have also used CS-193P Stanford classes. These might be better if you are a visual learner.
http://www.stanford.edu/class/cs193p/cgi-bin/drupal/
Another great resource has been this Design and Code website.