This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
Java Enterprise Edition requires an application server like JBoss, WebSphere or WebLogic. You'd need to most recent version to support JEE 5. The system requirements for that server will tell you what version of Java it uses. Java 5 and 6 are typical to expect.