Long time California forager Christopher Nyerges has been a survival skills educator for forty years. His newly released Guide to Wild Plants and Useful Plants is a terrific book for those interested in learning how to identify wild edibles.
For the person who wants to start learning about foraging for edible mushrooms, this e-book publication is the perfect starting point. Crash Course in Wild Mushroom Foraging has great images and critical information for the beginner.