Adding ViewController for MainWindow

I am new to iOS programming, just to warn you!

I'm using Xcode 4.2 to build a simple app. I have followed this Tutorial to create a MainWindow.xib after creating and empty application.

I want to show a scrollView where I can scroll horizontally between 2 pages (which I have done in tutorials, and therefore not worried about).

What I do need help with is this: as far as I understand, I would need to do the logic for my MainWindow.xib in the didFinishLaunchingWithOptions method.

I want to know how to abstract the code into another viewController. I would also like to know if this is the correct method to handle the logic, or if I'm misunderstanding something here (开发者_开发百科most likely).

There's a particularly easy to follow document by Apple about adding a view controller to the main window. Read it here!