This post guides you through your first steps with Cocoa. Its basic aim is making you gain enough intuition to let you guide yourself through Cocoa documentation in the future. If you have ever programmed in, e.g. Java, you know what this means: you first need to have some basic knowledge of the whole platform to get started and, at that point, you can do almost anything by driving to the API documentation and searching for what you need — even if you had no clue on how to accomplish your task before.
Attacking the in-depth documentation directly is hard because it overwhelms you with details that are not important to the beginner. Plus it does not show you the big picture.
I am by no means a Cocoa expert yet (in fact I'm very much a beginner), so this post will be extremely helpful to me, at least; thanks Andy! I hope it is to you too in case you wanted to begin programming for Mac OS X.