I picked up a couple volcano videos for the kids, at Marshall's of all places, and it turned out one of them was a documentary about the USGS and how it followed the whole eruption of the volcano from when there were first reports of it becoming active until it blew. There was some really impressive footage of the days just before and the actual eruption itself, mostly taken by soldiers at the military base there. The immensity of the whole thing is mind boggling. Fascinating video.
There's a book called "Volcano Cowboys" about the USGS and Mt. St. Helens, Pinatubo, and I think Nevado del Ruiz in Columbia, and about their prediction attempts, etc.
They had the easiest time at Pinatubo because it was easy to get the Air Force leadership to understand the science involved, because of their educational background.