You just navigate exactly the same way you would in a normal servlet/JSP application, although you use the include as opposed to the forward. So, figure out which page to show the client, and then show it!
For complex apps, we often see
JSF or
struts, but you can do the same thing with a portlet as the controller forwarding/including to different
JSP views.
My signature links have some portlet tutorials, which include a portlet that forwards to multiple JSPs.
-Cameron McKenzie