buy a book. It helps to have a reason for wanting to learn J2EE. Are you going to use it in a project of some sort? If you're just wanting to get into MVC style web applications, learn the Struts or Spring web frameworks. If you want to learn EJB's download JBOSS (free full J2EE appserver). If not, then you can just use Tomcat which doesn't have all the EJB stuff but everything else.