How to learn Axapta programming: “MorphXIT: an introduction to Axapta and the MorphX Development Suit”
I am very much excited about this book, and found there many tips and tricks I didn't know before. So, even though this book mostly dedicated to Axapta newbies, I think it will be interested and helpful for experienced developers as well. Ideally, in my opinion, will be right for people who already have some small experience with Axapta, something like 3-6 months for example.
You can find more information about it here: www.steenandreasen.com