This week's book giveaway is in the Android forum. We're giving away four copies of Create an Uber Clone in 7 Days: Build a real world full stack mobile app in Java and have Shai Almog on-line! See this thread for details.
The best materials I have come across are from the notes of Mikalai Zaikin (both EE5 and EE6 notes) and you can find some stuff in the old Sun Blueprint: Designing Web Services With the J2EE 1.4 Platform . Use Google as well to find interesting stuff.