Identifying quality fruits/vegetables at a farmers market
Some general rules for veggie hunting at your local farmers market.


Get there early and watch how they handle the produce, if they are rough unloading it chances are they where rough loading it.
Does it smell fresh and like the product you are buying. Beware some vendors use air fresheners and other products to hide the true smell.
If the deal seems to be too good to be true it probably is.
The firmness of a item is not always a good sign. Some fruits and veggies tend to get hard as they age.
Talk to the vendors ask them about where the item was grown. True farmers and craftsmen are usually proud of their items and will speak loving of it.
Don't be afraid to haggle, worse they can tell you is no.
Some produce can be very hazardous to your health if eaten rotten.
Check the items for wax or other preservatives


Some quick hints for the items you listed (please note this is in general and may not apply to the variety you are looking at)

Cherries - should be slightly firm and ooze juice if squeezed hard enough

Oranges - should smell fresh and be squeezable without being mushy or firm

Mushrooms - good coloring, should not be mushy, fresh murshrooms tend to be earthy smelling

Onions - firm, good onion smell, no eyes or growths (could always buy them to plant) look for dark spots if found unless they are small or you are going to eat it soon after walk on

Garlic - pretty much like a onion

Broccoli - look for firm very good coloring, check the nooks for bugs and worms

Celery - very firm, should have a good smell to them and should break with a crispy snap