Here are a list of books I would recommend to become a good IT expert.
The Pragmatic Programmer
I have learned so many good practices through this book which I think never gets old.
Enterprise Integration Patterns
Must read for all people working on Integration Platforms. It's especially important these days as there are many Big Data and IoT challenges.
Camel in action
How to implement Integration Patterns in real life using the famous Camel Integration Framework.