Transition To Raw Food
There are two schools of thought on transitioning your dog to a raw diet:
In the majority of dogs, regardless of age, the transition to a raw diet is best done immediately. Many have come to find that throwing out the kibble one day and introducing raw food the next day causes no issues whatsoever. To avoid the little bit of gastric upset a dog might go through, I recommend that you fast the dog (do not ever fast a puppy under a year of age) for at least 12 hours prior to feeding it's first raw meal. Happily, most dogs do very well switching to raw "cold turkey".
The other school of thought is to gradually introduce the raw food into whatever the dog is currently eating over about a one to two week period of time. While some dogs have extremely sensitive digestive tracts due to a long life of being fed kibble and over-exposure to chemicals, changing from any food to another type of food may very well cause at least minor GI upset. By gradually introducing the new raw food into the dog's diet, these dogs are slowly exposed to new foods without as much risk of gastric irritation. This is sometimes the best way to introduce dogs to the nutrient dense raw diet who are currently dealing with chronic illness or are senior dogs.
It is important to note here however that you NEVER want to add raw meat to a kibble or cooked food meal. Raw meat and bones are digested very quickly by the dog, in fact, in many cases within only a few hours. On the other hand, processed kibble or cooked foods which are not natural to the dog's digestive system have to remain in the digestive tract to further ferment and break down so the body can try to obtain some nutrition from it. It can take 12 to 24 hours for processed or cooked foods digest. If you mix the two at the same meal you are just asking for digestive upsets.
If you want to slowly transition your dog, then feed the kibble or cooked food meal by its self in the morning and the raw meal in the evening - giving the kibble or cooked meal some time to digest and hopefully be out of the dog's system.