This post was published more than a few years ago (on 2005-09-30) and may contain inaccurate technical information, outmoded thoughts, or cringe takes. Proceed at your own risk.
Cocoa 101: Object-Oriented Programming for the Masses, Part 1 and Part 2. Nice scratching the surface of the way Cocoa’s classes think, and
clearer that some of the books I have in its explanations of same.