[stared]

Forget documentation, look at tutorials (list here: https://github.com/mbostock/d3/wiki/Tutorials, for example look at this one: http://vogievetsky.github.io/IntroD3/).

And later - look at examples (https://github.com/mbostock/d3/wiki/Gallery or http://christopheviau.com/d3list/gallery.html). IMHO it is the best way to learn D3.js and data vis in general.

Some other links: https://delicious.com/stared/d3js