SuperVolcano, by Dr. John Savino and Marie D. Jones, is a book which scares the bejeebers out of a reader! Every premise within it ought to make you build an underground shelter, with super water and air filtering systems and greenhouse capabilities. It's the only way you'll survive the next "Big Blow"! The problem is that it would be nearly impossible to fully protect yourself in North America if the Big Blow happens--especially if it's in the Yellowstone area or in California! The resulting ash fall and "nuclear winter" scenarios will effectively destroy North America civilization as we know it--and have a very, very adverse impact on the rest of the world. If it happens somewhere else, say Indonesia, then North America might get off with a bit less destruction, but still all crops, cattle, and people would have a hard time of it. For example--if you breathe volcanic ash in, it combines with the moisture in your lungs to make a sort of concrete--you die from not being able to breathe: Marie's Disease.
The book suffers serious proofreading problems--at one point it was supposed to say "10 to 12 million years ago" but said "10 to 12 years ago"--a very large difference! There were more of those things throughout it. Still, I am going to keep extra water and food on hand--even more than I usually do for hurricane-prone Florida!