Juste some additional information : I'm using Jboss Portal 2.6
Package your portlet into a war. The descriptor file (*.xml) all go in WEB-INF, the portlet class you can put into WEB-INF/classes or package as a jar and put in WEB-INF/lib. If you have html, jsp, images, etc they go wherever you would put them into a typical war.
as far as i understand ur problem... there are 2 ways to make ur own portal
1. by packaging all ur .xml,jsp and .class files into war file and then deploy it by just copy the same into jboss-portal-2.6.2.GA\server\default\deploy\ folder. ur portal will reflect in the jboss portal.
2. in the jboss portal go to the admin link.this link comes after u log in by admin as username and password. go to home tab and then to portal objects... here u can create portal under the manage sub portals.
hope this will help.