Mapping Domain Objects to Datastores. Application Service Layers. But I recommend it even if you work with other J2EE implementations or you are advanced developer. The book discusses such topics as J2EE design patterns, roles of servlets and JSPs, tiered design of J2EE applications. The part on EJBs should be equally interesting for non-IBM developers.
Book exhibits good language, great explanations of the points made, and easy language.
Keep in mind it is also detailed introduction to WebSphere and VisualAge for Java, which takes roughly a quarter of the book. The CD has all software you might need to run examples. All rights reserved.