Starting it off,
This review is from: Quick Start Guide to Oracle Fusion Development: Oracle JDeveloper and Oracle ADF (Oracle Press) (Paperback)
ADF is huge. Not only that, it is catering to two very different types of developers: Oracle Forms developers and Java developers. This book sits well in the middle, getting both on their way to becoming ADF developers.
I started learning ADF as a Forms developer, and found the whole ADF framework a bit daunting to say the least. I read this book very carefully, and it gave me a good start. The framework is sliced up in nicely portioned bits, and served with enough details to actually make you see what it is going on.
We have used this book in my company for Java developers as well. They also appreciate the book, but on slightly different grounds than Forms developers. They enhance the explanations of "what actually goes on", "what actually goes where" and "how can I override default behavior", more than Forms developers.
The book is a "Start" mind you, and you are by no means an expert when finishing this book. But you will be wiser, and if you are starting ADF development, this will be well worth your while.