Be sure to buy and read a good field guide and get more than one book.
1. Make a positive identification using more than one source wherever possible. Do not eat mushrooms with any features that contradict the description. Contact a mushroom expert or club if you are not sure. “When in doubt, throw it out!”
2. Only pick specimens with opened caps. Mushrooms can easily be misidentified in the button stage.
3. Keep your known edibles separate from unknown species. Any unknown mushroom is possibly dangerous.
4. Take notes on all important aspects of the environment including types of trees, plants, other fungi, soil, forest or land characteristics, and any other unusual aspects of the location. It’s best to write it down and keep your notes with your finds.
5. Use every aspect of the physical structure for identification including a spore print. Spore prints should be made on black or white paper or glass.
6. Be able to distinguish a mushroom species from its close relatives and unrelated look-a-likes.
7. Learn and read what the deadly species look like and the symptoms of poisoning.
8. Avoid picking “little brown mushrooms” and difficult to identify or poisonous species like amanita, galerina, entoloma, and cortinarius. Beginners should also avoid lepiota, lactarius and russula species. Learn the basics of these genera so you can walk by them.
9. Never eat any bulbous based gilled mushroom growing from a sac or cup. Those are likely to be amanitas, many species of which, are deadly.
10. Avoid boletes with red or orange pores that stain blue. Blue staining mushrooms should always raise a caution flag although a few can be eaten. For beginners black staining mushrooms are best avoided too.
11. For beginners it’s safer to start by collecting mushrooms with pores, teeth and ridges rather than gilled mushrooms.
12. Avoid polluted, treated, or sprayed areas. Weed-less lawns should be avoided. Fruit tree orchards should be avoided unless you know for sure they haven’t been sprayed. Pesticide residues can remain in the soil for many years. Possibly decades. Lead arsenate stays in the soil even longer than the DDT that succeeded it.
13. Don’t pick next to busy, paved roadways. There could still be lead in the soil from leaded gasoline we used to burn and cadmium from tire rubber dust. On busy roadways pollution spreads from cars in a way similar to the dust cloud behind a cattle stampede.
14. Realize that there are no simple rules of thumb about edibility such as “if it stains a silver spoon….” or other generalizations.
15. Do not damage the environment. Avoid picking or knocking over mushrooms you don’t intend to keep. Fill any holes in the dirt or duff so the underlying mycelium does not dry out or become damaged. It’s best not to use a rake for finding matsutake. A good mushroom hunter leaves few traces behind.
16. Always cook your mushrooms thoroughly. There are bacteria in the outdoors and you could become ill from something entirely unrelated to the mushroom.
17. Only consume fresh specimens. Older specimens may be spoiling.
18. Chew them well and don’t over do it.
19. Try one new species at a time eating only a small amount at first retaining a sample of the new species in case of poisoning or allergic reaction. Just as some people can’t eat nuts, strawberries, shellfish or other foods, allergic responses to some mushrooms are certainly possible.
20. When fall rolls around and the hunting seasons begin, wear hunter orange in the woods at all times!
As with all rules and descriptions there are always exceptions. Size of mushrooms in particular can be quite variable. I have been puzzled on quite a number of occasions by mushrooms that were much larger than descriptions indicate. Every once in a while you will find 12 inch or larger boletes, horse mushrooms, oysters or others. I have learned that a 10 inch platterful or blewit is definitely possible. 2006 was a wet year and chanterelles commonly had 4-6 inch caps. It can throw you so realize that size can be much greater than field guide parameters suggest.