The Audubon Society's Field Guide to North American Mushrooms. Very good at identifying mushrooms. Has actual colored pictures of the mushrooms and gives good Descriptions along with Seasons, Habitat, Range, Look-a-likes, Edibility and Comments. The book is about 7"x4" and 1 1/2" thick fits well into your back pocket. The author is Gary Lincoff, President of the North American Mycological Association.