Theserverside is offering a free copy of Mastering EJB3.0. 

       Published in July 2006, the best selling book Mastering EJB
is now in its fourth edition and has been updated for EJB 3.0. This
edition features chapters on session beans and message-driven beans,
EJB-Java EE integration and advanced persistence concepts. In-depth
coverage of the Java Persistence API and using POJO entities with EJB
is also included.

 I  quickly browsed throug the book and it seems quite elaborate. Don’t forget to print the EJB annotation reference in appendix B, that looks really useful (shift+ctrl+plus is rotating the page in Adobe Reader if you don’t want to print or rotate your screen)

 You need to be registered to download the copy