Difficulties to define a navigation estructure

I want to create a blog with many sections (like, for exemple: sports, literature, international, politics, etc). These sections will have links to other pages. In this scheme, the first page is a general front page, the secundaries pages a kind of a subfrontpage and the only the third level pages are complete texts. How to do it? is better use pages or categories? How to insert copmentarie in second and thrid levels pages? Thanks