Over the past week I've been eating a handful daily right out of the thicket as I walked by. This morning I went picking on purpose, but I only stood in one small spot (the grass/weeds need to be mowed around the thicket) and picked two cups. The vines are just loaded, but most are still small and red, so it should be a good harvest over a long period of time.
While looking up some recipes I found Tips for Selection and Care of Blackberries:
Pick only ripe blackberries; these are black all over with no red drupelets. A gentle tug will release the blackberry from the stem. Handle blackberries gently; they are fragile. There is no need to wash blackberries before either using or freezing. Blackberries will keep in the refrigerator for about two (2) days if they are unwashed and stored in an uncovered container. To freeze blackberries, simply put them unwashed in freezer containers, seal, and place in freezer.
The site has a long page of recipes that sound yummy; it's well worth a visit!
Another site with berry recipes is here.