This is a tutorial on coding an iPhone App in XCode.
Similar to one of my first blog posts on building a basic application for Mac OS X using xcode 3.0, I am going to explain for beginning iPhone/iPod Touch developers how to build the most basic Cocoa Touch application using Interface Builder and an application delegate in xcode 3.1. This tutorial post is really to provide a quick how-to. I won't go into any depth explaining why things are done the way they are done, but this should help you get up and running with your first application pretty quickly so that you too can clog the App Store with useless superfluous apps (kidding… just kidding).
If you are a visual learner, it may be helpful to you to instead watch a video presentation of this tutorial. I've posted it on the site, but you'll have to click the link to see my Cocoa Touch Video Tutorial.
Understanding Cocoa programming is much simpler if you learn MVC, Model, View, Controller. You can probably step through code examples and figure some things out without learning MVC, but I wouldn't recommend it. Go Google it and read up on it.
As an introduction to MVC for those who are not familiar that it should probably be called (Model <--> Controller <--> View) or (View <--> Controller <--> Model) as the controller always sits between the other two. Your controller is either telling your model to update its data or it is telling the view to update its display. That's the crux of the whole paradigm. The details run much deeper, but that's how I will nutshell it for you.