Found in 2 comments on Hacker News
jtth · 2010-05-03 · Original thread
Hillegass is good, and I haven't read much of it, but Kochan is amazing, and I've read almost every word of it. It starts out with just the language itself, moves slowly, and assumes little programming experience. Then it moves you into Cocoa and UIKit and all that goodness, but only after you get the basics.
khelloworld · 2010-03-02 · Original thread
I suggest you start here:

Perhaps you can move to the book you have after you are reasonably comfortable with objective-c (and a little bit of cocoa).

Good luck.

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