Blog for multiple authors

First of all, I am completely new to wordpress – but am just exploring some options as to the best way forward for a new site I am developing for a book publishers.

The basic idea is to have one overarching project site, and then within that each of the publishers author would have their own blog and several pages about each of their books. Ideally this could information could all be pulled together for the main sites homepage (i.e. top/most recent posts) and potentially automatically post to Facebook/Twitter.

The site will need to be simple for each of our authors to be able to keep it up-to-date, though some may choose not to keep a blog and there could be just a few static pages within that.

Therefore the whole site will need an over-arching navigation in the theme, and then when you go down to each author, there will be almost a fully functioning wordpress blog (with its own second menu) below this header).

Basically what I am looking for is some advice on whether it would be best to set this up using WordPress multi-site, or whether it may best be served using a hierarchy of categories?

I realise I am probably going to have to learn to create a relatively complex theme to be able to do this, but just wondered if anyone had any suggestions as to the best way of approaching this project. The wide array of possibilities/features possible within WordPress are slightly baffling at first!