While far from complete, this list will give the average reader and enthusiast a good understanding of cryptozoology past and present:
Cryptozoology From A to Z - Loren Coleman
Unexplained - Jerome Clark
Cryptozoology: Science & Speculation: Cryptozoology - Chad Arment
A Dictionary of Cryptozoology: Dictionary of Cryptozoology - Ronan Coghlan
Moa - Richard Wolfe
The Last Tasmanian Tiger: The History and Extinction of the Thylacine - Robert Paddle
Dragons, Unicorns, and Sea Serpents: A classic study of the evidence for their existence - Charles Gould
When Elephants Weep - Jeffrey Masson
The Field Guide to Lake Monsters, Sea Serpents, and Other Mystery Denizens of the Deep - Loren Coleman
Mysterious Creatures - Jim Hicks (Time Life Books)
The Great New England Sea Serpent: An Account of Unknown Creatures Sighted by Many Respectable Persons Between 1638 and the Present Day - J.P. O'Neill
The Loch Ness Monster - Campbell Steuart
A living Dinosaur? In Search of Mokele-Mbembe - Dr. Roy P. Makal
This list will be added to periodically