I learned from books and double checking online for better photos.
So far the worst that has happened to me is harvesting some plants that had developed some sort of fungus that stunk up my kitchen when I cooked it. Obviously I didn't eat it as it smelled and cooked wrong and the water turned to slime which wasn't normal.
Also got into the habit of checking each berry for bugs and worm holes after eating a fire ant and it stinging the roof of my mouth before getting chewed up.
I rinsed them but I guess that little guy hung on.