I found This
Some of the tastiest and most interesting mushrooms are wild, but only about three percent of the wild mushrooms in the world are suitable for human consumption. Translation: “not suitable” means poisonous, so don’t go picking the mushrooms that sprout up in your yard after a damp spell or the beauties you find while hiking the woods.
And
There are a number of species of mushroom that are poisonous, and although some resemble certain edible species, eating them could be fatal. Eating mushrooms gathered in the wild is risky and should not be undertaken by individuals not knowledgeable in mushroom identification, unless the individuals limit themselves to a relatively small number of good edible species that are visually distinctive. More generally, and particularly with gilled mushrooms, separating edible from poisonous species requires meticulous attention to detail; there is no single trait by which all toxic mushrooms can be identified, nor one by which all edible mushrooms can be identified.
When I Was Young We Ate PuffBalls, Pan Fried In Butter, You Need To Make Sure They Are White (No Yellow) They Tested Good.
http://en.wikipedia.org/wiki/Puffball