Simply put, I want to learn OOP, concepts, thinking, etc. I have owned this Object-Oriented PHP: Concepts, Techniques, and Code which teaches OOP for PHP, that wasn't easy enough for me. Can anyone recommend an easy book to learn OOP?
I was looking at the following, but not sure if it covered the beginner well:
Head First Object-Oriented Analysis and Design
I didn't see anything from Sitepoint specifically...
Is there any online reading for learning OOP?