This instructional manual is designed to meet the needs of a diverse audience, including students, developers, and anyone wishing to develop a thorough understanding of the principles of object-oriented programming, with particular emphasis on the use of the Java language. Progressing sequentially, the guide explores the basics of object-oriented programming, detailing class creation, inheritance, polymorphism, and exception handling in Java. It also offers practical advice to ease the transition from procedural to object-oriented programming. Packed with concrete examples and practical exercises, this manual aims to be an essential companion for all those who aspire to master these fundamental programming concepts.