Anybody's Bike Book, Bike Tripping, both by Tom Cuthbertson
The books that got me (and many others) hooked on bikes as an adolescent

Paris-Roubaix:A Journey Through Hell
Big picture book about the famous one day bike race through history

No Hands: The Rise & Fall of...Schwinn... by Crown & Coleman
A lively account of the iconic American bicycle maker, and a good overview of bikes in the 20th century from two business journalists

C.O.N.I. Manual
Italian cycle training manual published in 1972. Priceless window on the sport- PDF available here: http://www.sandcreeksports.com/coni.htm