New Book: "NetBeans Platform for Beginners"
By Geertjan-Oracle on Dec 29, 2013
Though the book isn't available yet, a sample PDF can already be downloaded, as you can see in the image above. Reading through the preface, it seems all core NetBeans Platform topics will be covered, e.g., System FileSystem, Lookup, Nodes, and TopComponents.
The authors would like to know, on the page above, how much you'd like to pay for the book! So, read the PDF, look at the writing style and content, and at the introduction and preface to see whether it will match your needs. Then let them know what you'd pay for it!
It will be good to have an updated book on all the core NetBeans Platform topics again.