If you want to get serious about wild edibles, you need to get yourself a good field guide. My first handbook was Bradford Angiers' Feasting Free on Wild Edibles.

If you want to learn more about the role of sunlight in forest growth, and why plants flower when they do, you can't do better than The Forest Unseen: A Year's Watch in Nature by David George Haskell. Scientific in its detail, but very readable and engaging.

Here are two excellent articles that go into more detail about how and why we've bred the nourishment out of our eats (or just google "cultivated vegetables less nutritious than wild" for a host of others):

https://www.nytimes.com/2013/05/26/opinion/sunday/breeding-the-nutrition-out-of-our-food.html

https://www.motherjones.com/environment/2013/09/health-benefit-eating-weeds/

Leda Meredith, "The Forager's Feast," featuring wild edibles recipes. https://www.amazon.com/Foragers-Feast-Identify-Prepare-Countryman/dp/1581573065/ref=as_sl_pc_qf_sp_asin_til?tag=ledsurbhom-20&linkCode=w00&linkId=KPTYEDZYJ6IYZDEB&creativeASIN=1581573065

Another good one I bought recently: Northeast Foraging by Leda Meredith (I hope she won't mind the free plug.) Each entry contains "How to Identify," "Where and When to Gather," "How to Gather," "How to Eat," "How to Preserve, and "Warnings," along with information about the sensitivity of the plant to being harvested.

The Millyard Museum of the Manchester (NH) Historical Society has (or used to have) an outstanding visual exhibit about the changing New England landscape--highly recommended. https://www.manchesterhistoric.org/millyard-museum

Facebook Edible Wild Plants group. https://www.facebook.com/groups/ediblewildplants/permalink/10156439646753177/

New Friends the Human Kind