PlanetCatfish.com

For anyone into South American fishes, let me suggest a very good book. I just picked up a copy of Smithsonian's Atlas of the Amazon by Goulding, Barthem, and Ferreira (Smithsonian 2003). Fantastic! 150 maps and 289 photos of the various rivers and their environs. Specific chapters are devoted to the Amazon, Tocantins, Xingu and Tapajos, Madeira, Purus and Jurua valleys, Ucayali and Maronon valleys, Northwest tributaries, and the Negro and Trombetas. If you ever wanted to see great habitat shots of say the Xingu versus the Negro or Tocantins versus the Ucayali, you will spend hours looking at this book. The maps are also very helpful whether planning a collecting trip in the Amazon or just keeping track of where your fish come from.
-Shane
PS The Orinoco is not covered nor is the Magdalena, so I guess we just have to wait...

Shane,

I said the same thing (with a lot less words) in a post with exactly the same title here.
There is link to purchasing the book from Amazon.com (where Jools will get commission) there.