After six months of renovations to the former Little Gym space at Potomac Woods Plaza, O’Donnell’s Market opened its doors this week with a promising selection of fresh fish, seafood and baked goods. The store was just beginning to stock up when we stopped by on Wednesday, but owner Bill Edelblut says he’ll soon be adding a salad bar, grab-and-go items and a full-service bakery. O’Donnell’s isn’t cheap: Much of the seafood is priced around $25 a pound, and crab cakes are $10 apiece. But we were impressed with the super-fresh flounder, one of the more economical choices at $13.50 per pound. Edelblut has a long history in the seafood industry; his family owned the venerable O’Donnell’s Sea Grill restaurant chain, which closed its last remaining location at The Kentlands two years ago.