Here are some examples of common "weeds" that are edible and have numerous nutritional benefits.
Stinging Nettle (Must be boiled before made edible, must be collected with protective gloves to avoid injury)
Milk Thistle (Antidote for death cap mushroom poisoning.)
Wild Leeks (Ramps)
Blue Camas (Do not confuse with white-flowered camas, which is poisonous.)
There are many others. For more information, please visit the following websites.