I bought one of the Chancellor Press Country Guide books on Fungi from a discount book store for a couple of pounds. It`s one of a series on birds, trees here is & wild flowers. It has illustrations of all fungi found in Britain & Northern Europe with extensive descriptions of characteristics, habitat, similar species & most importantly, wether they`re edible or poisonous. Having read it, I`m still very wary, as some good ones are very similar to the toxic ones, & as the author points out there is no hard & fast rule applying to all fungi regarding edibility. There is no substitute, he states for careful study of characteristics & habit. It`s not a large book, so can be taken easily "in the field".