I recently got Ben Radford and Joe Nickell's 2006 book Lake Monster Mysteries: Investigating the World's Most Elusive Creatures. Some in the cryptozoological community may not like these two since they are skeptics and "don't believe" in the creatures they say are real. But, throughout this book, Radrod and Nickell give good cases for why, in fact, lake monsters are not real, including some very famous ones.
The two authors take a look at lake monsters from throughout the world, such as Nessie, Champ, Ogopogo, the Silver Lake monster, Cressie, Memphrie, and others. They point out that lots of supposed pieces of evidence for several of these creatures do not hold up under scrutiny, especially the Mansi Champ photo from 1977 that many champion as the best evidence for any lake monster. (Radford also had a fascinating discussion on this on a recent episode of Colin Schneider's Crypto-Kid). They also show how "Native American legends" and supposed "old stories" that cryptozoologists say are of lake monsters usually have nothing to do with them at all, and how many known animals can easily be mistaken as unknown creatures.
Those who are die-hard believers in lake monsters will probably not like anything Radford and Nickell put forward in this book. However, I feel that this is an extremely important book and it should be read by all those interested in the subject. It doesn't mean you can't be interested in lake monsters - just look at them from a different light.