Liferay is impressive. Extending and creating applications (portlets and integrations) is merely a piece of cake. Here’s the basic of all basic portlet development using Liferay. Portlet Framework 🙂
Basically, this is almost the same way of creating any generic portlet (portlet that complies with JSR – 168 / 268). It just forces you to use its underlying framework.
More Portlet Basic Tutorial (Database Transaction Tutorial)