I'll tell you how to get here ~ take I-95 North to the Walthall exit (I forget the number, the one immediately after Temple Road, exit 56). Turn right onto Ruffin Mill Road and go a little ways around the bend. Right before you get to the factory, there's a small gated entrance that leads into fields. That's the berry farm.
The best time to pick strawberries is early May. Any time after Mother's Day weekend is too late. My mom and I found out about Walthall Berry Farm after the farm we had been visiting stopped opening up to pickers. If you love strawberries, definitely treat yourself to fresh picked ones!
The prices at Walthall Berry Farm are inexpensive, but the berries add up! I picked $26 worth and I swear I was eating strawberries for weeks after. It's fun and easy, great for the whole family, and enjoyable in the spring weather before it turns really hot.
I'm not sure if they offer other fruits or vegetables for picking, but they do sell some fresh vegetables and they will sell strawberries picked by their own staff if you don't want to pick your own. You can buy them by the pound or by the pint, however you prefer.