Mastering Enterprise Java Beans published by Wiley has long been in my opinion one of the best books out there on EJBs. The lastest book on 3.0 is no longer written by Ed Roman, but two of the previous co-authors from the 3rd edition, Rima Patel Sriganesh and Gerald Brose now together with Micah Silverman have just published ‘Mastering Enterprise Javabeans 3.0’ which in following with the previous editions is available as a free download from TheServerSide.com.