Adding labels and descriptive label to D3.js donut chart

Question

I'm using the following d3.js donut chart: jsfiddel

What I would like to do is extend this example so that:

1. Each coloured section needs a text label

2. I want to colour in the centre of the donut, and add some text to the centre of the donut

3. I need to be able to style each path based on it's class, so how can I apply a class?

Any help appreciated, many of the samples for d3.js are hosted on a site which is currently down .