For you guys that pick them, cut them off the stem on the ground and there'll be less dirt and needles to clean at home. Most are wet. Store them in a paper bag until you get home. If they're really dirty, wash them off. If not really dirty, use a brush for the few spots you need to get the debris off. Put them uncovered in a large bowl in the fridge and they can dry for a couple of days if needed. When they are dry, the remaining needles will just fall off if you shake the bowl. When cooking wet mushrooms, as stated above, dry cook them until the excess water has evaporated. If there's a lot of water, you can always pour some off. But remember: there's flavor in that water.
half olive oil, half butter (2 oz ea)
Cut the shrooms in 1/2" thick slices and sauté in the butter and oil until the liquid is gone and the bottom of the pan is glistening with the sugars from the shrooms. Add salt, garlic powder, and pepper and stir/flip/whatever. Finish with 2oz of sherry or sherry vinegar, deglazing the pan and reducing liquid to nothing again. Eat them. Add them to salads, pasta, fish, meat.