Never cook bones -- this causes them to splinter more easily and makes them very hazardous to dogs. The one exception is the bones that are really hard cooked that you can get from pet shops -- they are like rocks! Vets and raw proponents both are VERY clear on this -- cooked bones are extremely dangerous and the major cause of gut and stomach punctures -- which are often fatal!! The most dangerous of all are cooked chicken or poultry bones as they easily splinter when eaten and won't digest down at all -- they remain in hard shards thru the intestine. :yikes.
Many people these days feed raw diets and are very happy with the results; while historically (until only the past few decades!) many dogs were fed the raw off-cuttings from butchers and it doesn't give them a taste for blood (any more than eating a black pudding or a rare steak ot steak tartare makes people hanker after a blood
). But from the dog's point of view -- such things taste very good compared to a diet of dried food or tinned so no wonder they go crazy for bones, and can become very protective.
Feeding bones (and raw diets) though remains very controversial. The majority of vets will say not to, and will say there are always risks from any animal chewing on any bones whether it is eaten completely (like chicken wings or necks) or gnawed (large joint bones or marrow bones). On the opposite side, there is a dedicated raw feeding, 'bones and raw food (barf)' perspective -- with a couple of vets as the key proponents -- who feel feeding bones and raw meat is a better diet choice. There's a lot of info out on the web on both perspectives. But it won't make dogs hungry for (people) blood -- or more prone to bite, whch seems to be the old story as I've heard that too from friends.
Personally, I won't feed raw any longer based on the scientific studies that do exist for risk of ingestion of dangerous organisms and also for problems with splintering bones. I have seen one of my own dogs come close to a 3am trip to the emergency room because he was in increasing distress until he finally brought up a raw chicken wing he'd eaten over 12 hours earlier, with the bone shattered into large, extremely sharp pieces. According to barf proponents this is supposed to be impossible as a dog is supposed to digest bone and the raw meat quickly. But I saw the evidence otherwise and was horrified at the size and sharpness of the bones, which hed seemed to chew down when he was eating the wing. I also have read quite a few interviews with people who run wolf sanctuaries or who are specialists on wolves and wild canids who would dispute many of the claims put forward on behalf of raw diets, even for wolves (amongst them being that they say there's good evidence that wolves do die from punctured guts from eating raw bones -- and that the life of a wolf in captivity, where they are not often fed raw meat or bones, is three to four times as long as wolves in the wild, suggesting they don't suffer from poorer nutrition and greater health risks when eating a more conventional dog-style diet).
Others feel they see real and very positivie health benefits from feeding raw and offering lots of bones to gnaw or eat entirely so the best approach is really to read widely (I have some links in the Library section for example). There are whole books that can be bought giving directions on feeding raw (guidnace is needed as just giving a dog chicken wings or necks is not a balanced diet and has serious nutritional gaps).
If you want to offer raw bones for gnawing, you could ask the butcher to give you maybe three to four inch sections of marrow bone. Personally I am a lot more comfortable with large bones for gnawing than bones that are chewed and digested for the reasons noted before. To offer chews that that give them good satisfaction but are not raw, I give a lot of hard chew treats that I get from zooplus.ie -- the tendons are really good for example, as are pizzle sticks and dried tripe.