This structure of site is based on module Book in Drupal core. The site benefits from pathauto module to create paths automatically.
Other modules that I used are:
I've tried to implement Drupal themes search as I imagine that and as I want it to be.
(+ modules search (I like drupalmodules.com, but they seems to be stopped to support that).
Its still work in progress, but would love some advise as how I could make it better.
Theme will be in work as well, for now I am using one of the free ones that I've worked with in the beginning, so I am staying with that one until I get a custom one.