These three books helped me tremendously: 1. The Pragmatic Programmer by Andy Hunt and Dave Thomas 2. The Clean Coder by Robert Martin 3. Design Patterns: El

These three books helped me tremendously: 1. The Pragmatic Programmer by Andy Hunt and Dave Thomas 2. The Clean Coder by Robert Martin 3. Design Patterns: Elements of Reusable Object-Oriented Software (the "Gang of Four" book) The first two contain a range of advice pertaining to working as a professional software engineer. The third one, although very dated, is still a great resource for understanding many of the design patterns used in OOP.