I'll second that, Scafool. Mushrooms are some of the most useful wild edibles (in temperate woodland at least). I grew up in a family where gathering mushrooms has a long tradition that goes further back than anyone can remember. It actually takes very little effort to learn the basics - how to identify several of the most common edible species and which ones to avoid at all cost. But this is one thing that can't be learned from a book and it's highly location-specific. You need some hands-on guidance and a bit of practice.

Pick only those mushrooms you're totally sure about and you'll be fine. I've eaten plenty of mushrooms in my time, can't say I'm a big fan but they're a decent source of food. Too bad they tend to grow only in specific locations. Also, the weather has to be just right, warm and wet.