Head First Java by Kathy Sierra and Bert Bates (E-book)
Head First Java combines strong visuals, puzzles, mysteries, and soul-searching interviews with famous Java objects to engage you in many different ways. It’s fast, it’s fun, and it’s effective. And, despite its playful appearance, Head First Java is serious stuff: a complete introduction to object-oriented programming and Java. From the fundamentals to advanced topics, including threads, network sockets, and distributed programming with RMI, everything can be learnt. So if you are thinking to learn Object Oriented Programming in a fun way, your search ends here!