The Library Book by Susan Orleans

This is a masterful tribute to libraries, and, even better than that, it has a plot and a story line.  On April 29, 1986, a fire consumed or damaged more than a million books in the main branch of the Los Angeles Public Library.   It was an inferno that burned for seven hours.  As you can imagine, there was a lot of flammable material held within.
The fire that nearly destroys a collection, leads Orlean to histories of libraries and Los Angeles and to an exploration of the physics of how a book burns.  There’s a suspected arsonist at the center of the story, but the hero is the library along with its collections of books, maps, menus, autographs and marionettes.
She goes on to explore the role of libraries in contemporary American life, which has gone well beyond the boundaries of books, or even things that are printed.  It includes multi-media, it has a social role, it is a place of safety and learning.  All that is beautifully laid out within this book.