As I've been trying to intimate, this is not a quick and simple task on WebSphere. Please take your time to go and read the linked documentation (especially the tutorial on deploying an EJB application). There is no shortcut.
What you would typically do (as the link explains) is create your application, then prepare it for deployment (either using an admin script written in Jython or TCL or in a WebSphere IDE, such as Rational Software Architect). This will do the stuff you cannot do by hand (e.g. create the WAS specific classes and add generated identifiers to your elements in your deployment descriptor). Then, assuming you have set up any container resources your application relies on,
you should be able to deploy it.
Note: the web client admin console will do much of this, but in WAS 6.0 is is missing certain important parts that will prevent you from using it exclusively.