A lot of times the reason the animals haven't touched the fruits is because they aren't ripe. This is true of things like gooseberries, wild grapes, elderberries, russian olives, and currants. The most extreme one around here is the chokecherry. These ripen in the fall and you can eat them but they are so tart you will want to spit them out, hence the name. However, once a frost hits them, they turn sweet and the deer love them.
Mushrooms are harvestable in the Spring and the Fall (mostly). But, no amount of description will make them recognizable. Hunt them with an expert.
Wild onions, wild garlic and wild carrots are easy. Once dug, give them a sniff. There are plenty of other things like poke salad that are only edible for a short time before becoming toxic. And always cook the wild asparagus you cut. It's toxic too.
I could print a list of things you can find but it's not going to do you any good unless you know what you're looking for. Illustrated books are a help but it's still best to have an expert with you.