http://earthquake.usgs.gov/activity/world.html

Loads of info as to what is going on - maps of current earthquakes around the world, and you can check out the last 30 days as well. earthquakes are shown as a little coloured circle; if you click on them you get another close up map and info to go with it

http://www.seismo.unr.edu/ftp/pub/louie/class/100/plate-tectonics.html

A great guide to plate tectonics and earthquakes, more links from the bottom of the page.

http://www.pbs.org/wnet/savageearth/earthquakes/

Another great site with some really cute and useful animations also has links to similar on Tsunami and Volcanoes.