Try Feasting Free on Wild Edibles by Bradford Angier
You should check Peters guides for Edibles & Poisonous plants.
The first step in wild edibles is knowing what is poisonous raw & what can be cooked & eaten safely.
Example: Nightshade plants, leaves & stems are poisonous.
Tomatoes,white potatoes,sweet & hot peppers,egg plants are all in the Nightshade family.
As many of you know these plant fruits are safe to eat, well some of the hot peppers are not "safe", but not poisonous.