what is the Best way to learn object oriented principles
<p>I am interesed in OOP principles and i found lots of documentations and books about it, for instance in C++, Java, .NET, PHP and so on, but if i only want to learn OOP principle, differences and not in language, what can i do? i want a good documentation, not just like a whole book about something except OOP :) specific answers, how it works, main features, pictures, or videos, or forum, or even stack... 
in every time I began studying i read a whole history of programming, computer science, software development and bla bla... i need specific answers, if it is possible</p>

<p>i really need to learn, i need
<strong><em>examples and exercises</em></strong></p>

<p>thanks in advance</p>
