Blackberries are shiny black fruit that has taken over many a hedgerow throughout the country. It has been commercially cultivated for over 100 years in the United States. Eaten fresh, blackberries are excellent, however most are mad into preserves, or are frozen.  Blackberries are super healthy for you.
Blackberries were used medicinally up to the 16th
century as treatment of infections of the eye and
mouth. Anthocyanins - Blackberries are characterized by
one major pigment: cyanidin-3-glucoside and in
some cases cyanidin 3-rutinoside. The total
anthocyani concentration is reported as 148
mg/100 g fruit. Phenolics - Similar to raspberries, blackberries
are relatively high in the phenolics, hydroxybenzoic
acid and chlorogenic acid. Fiber - Blackberries are high in fiber (5.3 g/100 g,)which has been shown to help reduce the risk of
certain cancers. 

Here is a complete site for blackberries as well as other related berries from the folks in Oregon:
http://www.oregon-berries.com/

Here is a good site for some blackberry recipes.
http://www.garvick.com/users/vwild/recipes/blackberries.htm