This week's book giveaway is in the Performance forum. We're giving away four copies of The Java Performance Companion and have Charlie Hunt, Monica Beckwith, Poonam Parhar, & Bengt Rutisson on-line! See this thread for details.
There is no such thing as a Session Bean in the context of Servlets. Servlets do have the HttpSession, which is used to store state for a single client between requests. "Session Bean" noramally refers to EJBs. To find out about these read the JEE tutorial.