Maximum LEGO EV3: Building Robots with Java Brains (Lego Mindstorms Ev3) Paperback – 22 Sept. 2014

Along with lejos.org this book is the best source of information on ev3 and lejos.Just make sure you run the latest version of lejos on your ev3 (sourceforge will help ya;)), otherwise things like ColorAdapter may not work (unless you will create your own version).

nice