We see that you have Guns, Germs and Steel on your To-Be-Read list. This is, indeed, a book not to be missed. Not only is it fascinating reading, but it also gives tremendous insight into why it was the Europeans who conquered the New World, and not vice versa.

Collapse is also to be recommended for its insight into the [often puzzling] 'whys' of the rise and falls of world civilizations.

Another nonfiction book not to be missed, is Bryson's A Short History of Nearly Everything. Amusing, as all Bryson's books are, and very informative, in fact, about 'nearly everything'.