We can't stress it enough: be absolutely certain of your identifications, and that the mushrooms you have are edible. Some types of edible mushrooms listed in our Field Guide include:
Wild mushrooms should never be eaten raw. They can be difficult to digest, and cooking will destroy any potential toxins.
The first time you eat any wild mushroom, put a few aside in the refrigerator. This way if someone has an allergic or poisonous reaction, an expert can make a clear identification and use the correct remedy.
All wild mushrooms should be cooked and eaten immediately, or preserved right away.
Some mushrooms may last a few days in the refrigerator stored in a container that lets in air and moisture, such as a glass or plastic bowl with a damp towel over the top.
Before cooking, most mushrooms should be cut in half from top to bottom or torn apart, and then checked for insects.
After cutting morels lengthwise, many people soak them in lightly salted water for a few minutes to get insects out of the pores and hollow stem. (You can verify your morels’ ID if you see a hollow stem.)
Some mushrooms are more delicate or dirtier than others. You can use a damp cloth or buy special mushroom brushes. If you can't brush off the dirt, you may have to rinse them with water.
Opinions vary about using water to clean mushrooms. Sometimes, they're so dirty you need to use water, but try not to get them too soaked. (Best of all is prevention: When you're out collecting them, put only clean mushrooms into your basket. Cut off the dirty, below-ground portions before they even go into your basket.)
If you use water to clean them, let them drain before cooking them. (Mushrooms are mostly water, so adding more water during cooking is unnecessary.)
Of course, trim off any rotting or unwholesome parts.