Implementing a Solution Using EJB 2.1

This is a very nice and detailed article of how to use EJB as solution provider.
Have a look here

Other EJB Stuff: Deploy EJB Application

Packaging EJB 3 Applications

Confused about packaging and deployment of EJB applications? What to put in jar,ear OR war files? This is really a detailed and useful article regarding application packaging and deployment. The article also provides critical information on class loading, so that you can appreciate why the archives are packaged as they are. This is intended to provide you a better understanding of the packaging requirements for EJB that include entities.

Read full Article here.