EJBs are not about XMLs and interfaces any more. They offer a simplified, declarative and POJO based programming model powered by annotations. These are used by the the container to weave its magic at runtime. In other words, the container does all the heavy lifting for you once you communicate your requirements via annotations.

This book consists of short chapters, each of which cover a specific part of the EJB specification. Here is a comprehensive list - life cycle management, dependency & resource injection, pooling, concurrency, web services, interceptors, security, transactions, schedulers & timers, asynchronous model, eager initialization, heterogenous interfaces/views and exception handling.