While not specifically a WWI book, William Manchester’s, “The Arms of Krupp,” is a good read and gives a lot of insight into the mindset that brought about the war...
“The Myth of the Great War”
http://www.amazon.com/The-Myth-Great-War-Military/dp/0060084332
“Miracle at Belleau Wood: The Birth of the Modern U.S. Marine Corps”
http://www.amazon.com/Miracle-Belleau-Wood-Modern-Marine/dp/076276130X
Also, I was going to recommend “The Arms of Krupp” (Krupp went under after WWII), but I see Joe 6-pack already did.
oh yeah, and this one, which goes through the architectual work that pushed the entire world into WWII, and isn’t too much of a cheerleader for the imbecile Woodrow Wilson.
“Paris 1919: Six Months That Changed the World”
http://www.amazon.com/Paris-1919-Months-Changed-World/dp/0375760520