Useful Links

JSP implicit Objects
http://java.sun.com/javaee/5/docs/tutorial/doc/bnahq.html#bnaij
Old version of J2EE link
http://java.sun.com/j2ee/tutorial/1_3-fcs/doc/JSPIntro7.html

Documentation Regarding HttpServletRequest Interface
http://java.sun.com/javaee/5/docs/api/javax/servlet/http/HttpServletRequest.html
Look into the methods of javax.servlet.ServletRequest Interface

Documentation Regarding HttpServletResponse Interface
http://java.sun.com/javaee/5/docs/api/javax/servlet/http/HttpServletResponse.html
Look into the methods of javax.servlet.ServletResponse Interface.

Documentation Regarding HttpSession Object
http://java.sun.com/javaee/5/docs/api/javax/servlet/http/HttpSession.html

Difference Between Web Server and Application Server
http://www.javaworld.com/javaqa/2002-08/01-qa-0823-appvswebserver.html