There is some good step by step instructions on what goes into the .jar file (e.g. ejb-jar.xml) for a bean in the "Bean Deployment" or "Deploying Beans" section of the WebLogic documentation. That documentation should be present in your installation. Just start with the top level .html file present in your weblogic install and
you should be able to navigate to the specific information you are looking for.
The section for developers in that documentation explains some things pretty well as well.
