I have been using D3 for a while, but just for doing simple graphics (lineCharts, barCharts).
In order to use the information, I will recommend you to use JSON format to store the CSV data in an object.
I have found this example on the web, by the creator of D3: http://bost.ocks.org/mike/map/
Hope it help you a little, it will be nice if you put some fiddle when the work is done