Alright, here we go: Now we have some rough plate tectonics in place. Red = Divergent plate boundaries; blue = convergent, yellow = transform. Black triangles mark zones of major volcanic activity; the orangy circles are hotspots. I've also started to add major mountain ranges (the brownish areas). This isn't perfect; it's fairly hard, in my opinion, to work out correct plate tectonics for pre-existing continents. There's going to be revisions as work on the world progresses, but this gives me something to start from.