Three level navigation using posts

Hi

I’m about to start working on a WP site for a client and I’m tearing my hair out with a structure problem.

I’m trying to create a three level navigation using posts. It has to be posts rather than pages because I’m using a rating plugin which uses the post Id.

This is what I need to achieve:

Level One – Home page which pulls in post excerpts from the next level down. I can do this by assigning a category to those posts I want to appear.

Level Two – A post that will have two or three other posts relating to it from the next level down. This post with pull in excerpts from those related two or three posts.

Level Three – Single posts that can be accessed via the level two post.

Hope that makes sense, would really appreciate help.
Thanks
Leanda