When I was out taking mushroom photos, I came across two people from Europe with a basket full of hen of the woods as well as a bag of honey mushrooms, both gathered from the bases of oaks. I learned the number of edible mushrooms each person can collect is limited where they come from, but here, where there are no such limits, they had gathered so many they would need to give some away.
They explained that the best way to learn which mushrooms safe to eat is to go out with an expert local guide. But books and online resources (like this one) can be helpful.
In addition to being eaten as food and medicine, mushrooms can have profound cultural significance. Those with psychotropic properties are used in healing rituals. The Maya carved wonderful anthropomorphic mushroom stones, and a jade pendant bears witness to the significance the Chinese place on mushrooms with their important role in traditional medicine.
Fungi support the health of forests and can survive fire. They have been used to control insect pests and to clean up plastic and organic waste. No doubt our appreciation for what they can do will increase as we learn more about them.