The problem with WWI is no one book will cover it all.
Also the author's view point can cause problems. Some are of the "lions led by donkeys" point of view, others have their own view of events that they put across.
If you really want to know about WWI, its causes, implications, aftermath and so on, you will need to read a large number of books, including as many first hand accounts as possible, before you can make your own mind up.
Lyn MacDonald has written a number of in depth books taking each year of the conflict in turn, and a couple of books on individual battles, that are very good.