Blood can be used to make some really tasty delicacies, and it's very nutritious and satieting.
Sangette is a traditional French peasant dish (made with poultry or duck blood, or any blood) that is tasty and really easy to make. (It's sometimes described loosely as a "blood omelette," but to me that just sounds nasty and doesn't actually do it justice.) We make it whenever we slaughter. It's best to use the blood when it's as fresh as possible. Simply saute some onions and garlic with chopped parsley in a skillet, add the blood, seasoned with salt and pepper, cook till the blood solidifies (you can cook it like an omelette, in one piece, or just scramble, which is easier). Garnish with more parsley and eat with buttered toast.
Scandinavian style blood pudding involves a little more prep, but is insanely delicious! You should be able to find a general recipe for guidance online if you dig around, or you can pm me. It's usually made with pork blood traditionally but any blood is just as good. Blood pudding is fun because once it's cooked and sets up, you keep it refridgerated and slice off pieces as needed and fry them in butter to crisp the outsides. Kind of like most people do with scrapple.
Some stews also use blood as thickener, including traditional Coq au Vin. But I'm not sure how that's done...