A friend forwarded this link. I went through it and it is a SUPERB article to learn photography. You should also read the articles in http://photo.net eventually.
This is an EJB 3 tutorial to help you learn about EJB 3 differences and understand how it can be used. By reading this EJB tutorial you will learn the main concepts, work with EJB 3 source code examples. The EJB 3 videos and demonstrations make this EJB3 tutorial easy to follow. EJB source code is available to download.
Access tutorial here