Give the caps a good soaking and cleaning to dislodge the small black beetles that like to nest between the gills. There are a number of mushroom cook books with a variety of recipes for oyster mushrooms and others. Easy, if not the easiest to spot. These white globes can be as small as an inch in diameter to as large as a foot, and are commonly found in open woods or fields. Take them only while fresh and firm.
Puffballs are good eating when sliced, dipped in batter, and fried.
To check them in the field, slice from top to bottom. They should be pure white and uniformly featureless inside. If there's anything that looks like an emerging mushroom inside, it's not a puffball you've found. It could be a deadly poisonous variety such as an amanita and should be immediately discarded. There are many types of mushrooms to be found in the woods and fields.