An interesting thing to do with those big beautiful mushrooms is to make a spore sprint.
Cut the stem off the cap of the 'shroom, and lay it gills down on a sheet of paper and leave it undisturbed overnight.
The spores (like seeds) are formed in the gills, and when the mushroom is fully open, the spores drop out.
When you pick up the mushroom cap in the morning, the paper will have a perfect print of the underside of the mushroom, made of the spores. If you want to keep the picture, you have to spray it with fixative or aerasol hair spray.
Some mushrooms have white spores, which won't show on white paper, so you might try two caps, one on white and one on colored paper. Kids love this, and it is perfectly safe. Do have them wash their hands after handling the mushroom, and make sure little ones know not to put the mushroom in their mouth.
I just haven't been the same
since that house fell on my sister.