I've been programming professionally in C, and only C, for around 10 years in a variety of roles.

As would be normal to expect, I understand the idioms of the language fairly well and beyond that also some of the design nuances - which APIs to make public, who calls what, who does what, what is supposed to reentrant and so on. I grew up reading 'Writing Solid Code', it's early C edition, not the one based on C++.

However, I've never ever programmed in an OO language. Now, I want to migrate to writing applications for iPhone (maybe android), so want to learn to use Objective-C and use it with a degree of competence fitting a professional programmer.

How do I wrap my head around the OO stuff? What would be your smallest reading list suggestion to me.

Is there a book that carries some sort of relatively real world example OO design Objective-C?

Besides, the reading what source code would you recommend me to go through.

How to learn OO paradigm using Objective-C?