The MSM has a series of terrific interactive charts, maps and animations:
Let’s start with the WSJ‘s Pacific/Australian tectonic plates. Note how many major earthquakes have occurred in this region.
click for larger chart, go here for article and interactive graphic
Next up is the NYT, which first looks at both how reactors work:
Japan’s Nuclear Crisis Escalates (WSJ)
Panic Selling in Japan Weighs on Global Markets (NYT)
How a Reactor Shuts Down and What Happens in a Meltdown (NYT)