Kiss Your Ash Goodbye: The Yellowstone Supervolcano

A quick read and a good primer on super-volcanoes, focusing on Yellowstone. It doesn't feel dumbed down though it is written to be accessible to the non-specialist. Osborn corrects some common misconceptions and gives specific numbers about the history of eruptions (volume, type, frequency, extent, and composition). I gained new knowledge from this little book about the structure of the Yellowstone super-volcano – specifically about the size and extent of the hotspot, plume, and magma chambers (that's right, plural). The numerous illustrations and tables are useful.
The slightly snarky title notwithstanding, KYAG is a pretty good introductory science book.