Please see Object Oriented Paradigm.
One way to get a wonderful feeling for what is involved would be to read Alan Kay’s The Early History of Smalltalk
Sun’s concise treatment, in Lesson: Object-Oriented Programming Concepts tutorial on sun part of the Java Tutorial
And then, as always, Wikipedia’s article on Object-Oriented Programming.
The best book in my opinion continues to be Timothy Budd’s An Introduction to Object-Oriented Programming in any of its editions, this is the third.
Check out the Table of Contents (I think several chapters are available on-line, as well as slides and additional material; check out the earlier editions, too):
Anyone interested in doing Object Oriented work, cannot afford not to read this material, it seems to me.
In fact, check out all his books
Content
Victor Kane (ProjectMaster) and awebfactory.com.ar