I failed to get started with ofbiz development in the past using the online documentation and other training material. This book managed to get me up and running in no time. There was a lot more that I needed to learn after reading this book, but this book got me started. I frequently use this book as a reference. If you want a thorough understanding of ofbiz development, you will also need a good knowledge of java web app development.
This book does jump around a bit which is why I have only given it 4 stars.
