With voluminous coverage of the continuing eruption of Iceland’s Eyjafjallajokull volcano and its wide-ranging disruptive effects, current interest in volcanism is high; but much reporting has concentrated on the immediate and transitory phenomena rather than the deeper context.
If you’re interested in a little something more, you might try, for starters, the quick introduction to How Volcanoes Work at HowStuffWorks.com, followed by Robert I. Tilling’s short monograph on Volcanoes at the US Geological Survey site, and a related USGS monograph on Volcanoes of the United States by Steven R.Brantley.
The USGS also has an excellent detailed map of volcanoes, earthquakes, impact craters and plate tectonics at The Dynamic Planet. (You might also want to take a quick look at the USGS page for Current Alerts for US Volcanoes.)
For items more directly related to the current Icelandic eruption, see Volcanic Eruption in Iceland Unlikely to Have Global Effects,
Iceland Volcano Could Continue Erupting for More Than a Month and Icelandic Volcanoes Can be Unpredictable and Dangerous in Science Daily, Get Ready for Decades of Icelandic Fireworks in New Scientist and Icelandic Volcanoes Disrupting Weather History Since 1783 in Discover Magazine’s 80beats Blog.