Thanks PARS fo ryour reply.
I have been building APEX apps for quite some time. But the new packaged apps are giving a new interface paradigm, that I would like to follow. So, I am looking for a guide that will step through the new paradigm. It could save significant time and teach all those new methodologies.
There is no such guide for packaged application, once you know all component of apex then not hard to develope application.
You can start understanding the packeged applications by looking at two things:
1) Category of the app
2) Overview Information stated when you select to install one