A World Undone, by G. J. Meyer

This is an excellent choice for those who are looking for a good overall history of World War I, who have not studied this war before, or the background history of the major players.  For the amount of material it covers, it is a short book.  G. J. Meyer intersperses "Background" sections at well chosen points in his narrative, that give information about persons, countries, or other entities that the reader is about to encounter, such as the Ottoman Empire, for example, or the Romanovs.

This is only the second book I've read about World War I, after Barbara Tuchman's <i>Guns of August</i>, and compared to that book, which focuses primarily on the Western front, this one gives a more comprehensive view.