I'm also interested in hearing about what people think about dotnetnuke as an application framework.
I have only just started learning about dotnetnuke and am trying to convince my boss to allow me some time to try it out.

I have an existing web app with about 10 pages in it. It allows users to view database records and edit, add, delete records and load data into the database by executing SSIS packages....

I'm thinking it would be great to integrate this app with dotnetnuke in some way so that we can take advantage of the access control and user profiles and all that good stuff.. being able to skin the site and add in third party modules is an exciting prospect...
I'm promise I AM going to dig into the documentation.. but before I do it would be great jsut to have some idea of what it is I'm trying to achieve..

Should I be thinking in terms of writing a module into which my app would fit? Or would I use some other mechanism?
The current pages of my app are pretty much full size pages.. would it be right to think of a module as taking up most of a page (I suppose the news module can eh?)

Thanks
Vida

PS: while I'm here, someone put me out of my misery and tell me what do I need to learn about before I can get a nice vertical menu like they have on http://www.itag.ie ????