I love blood sausage. It's delicious and the name is a bit misleading.
The blood sausage I know is made of ground pork and spices (sage especially), rice, etc. There's probably only a small amount of "blood" per ton of sausage. It's all packed in a natural casing and sold in rings.
I put a ring on a baking sheet and bake it at 350 degrees for about 1 hour. Turn after 30 minutes. The casing gets nice and crispy and the sausage inside is piping hot and delicious.
Blood sausage was always a special treat served at Christmas and Easter. It's been a tradition in my family.
I get my blood sausage at Paul's Italian Market in Eveleth, Minnesota. See this link
Don't be turned off by the name, it's delicious.