A good introduction is Bougainville: the Long Struggle for Freedom, By Moses and Rikha Havini.
There is still trouble there now, communications with the outside world are very difficult.
Click on the map to get a larger version in a new window. There is a more detailed scalable map of the island here in .pdf format.
The Drawings Gallery has some drawings done by bougainville children who went through the war years. They say more than words can.