I read all kinds of stuff--not just books about rivers and paddling. But here on my paddling website I'll share a few of the most memorable works on that topic that I've read.
 

Author	Title	ISBN	Elmore's comment
Edward Abbey	Down the River	0-452-26563-0	This book is not restricted to river-related essays, and essays about rivers do appear in other Abbey collections, but this is as good a cross-section of Abbey's essays as any in print
Todd Balf	The Last River: The Tragic Race for Shangri-La	0-609-80801-X	A gripping account of the expedition into Tibet's Tsangpo Gorge by a group of veteran slalom and wildwater racers from the U.S.
James Dickey	Deliverance	0-440-11868-9	The novel that inspired the famous motion picture; fortunately not an accurate portrayal of the typical paddling trip
David James Duncan	The River Why	0-553-34486-2	An engaging novel about a devoted fly fisherman on the Oregon coast
Eddy L. Harris	Mississippi Solo	0-06-097247-5	A journalist's account of his canoe trip down the Mississippi River from Lake Itasca to New Orleans
Katie Lee	All My Rivers Are Gone: A Journey of Discovery Through Glen Canyon	1-55566-228-5	Folk singer Lee pays tribute to the Eden-like beauty of Glen Canyon before it was buried beneath Powell Reservoir
Aldo Leopold	A Sand County Almanac	0-19-500777-8	An iconic collection of essays on the relationship between the human being and the land he lives on
R.M. Patterson	Dangerous River	0-7737-2308-0	An Englishman's journal of his life as a hunter and trapper in the unforgiving Northwest Territory
Marc Reisner	Cadillac Desert: The American West and its Disappearing Water	0 14 01.17824 4	A brilliant cautionary tale that has never been more relevant than it is today
Ron Watters	Never Turn Back: The Life of Whitewater Pioneer Walt Blackadar	1-877625-63-5	A biography of the man who pioneered Alaskan whitewater runs that remain on the cutting edge of river navigation
Doug Wheat	The Floater's Guide to Colorado	0-934318-16-6	Though rather dated as a river guide, this book contains timeless historical accounts of the role rivers played in the shaping of the West