I'll bet the best answer to this question would lie in some of the raw feeding sites that Serena has stored in that head of hers.
Common sense would dictate that you shouldn't feed your dog junk food, and there's an article posted here about the dangers of feeding grapes and raisins to dogs. Chocolate is a No-No (there's another thread with a link to an article if I remember correctly), and you have to be careful about letting them eat apple cores because the seeds contain small amounts of arsenic. Peach, apricot, nectarine and plum pits are also poisonous, I believe. Iceberg lettuce isn't good for them (but it's not particularly good for us, either.)
Chicken bones are dangerous, as are many cooked bones. A dog shouldn't have a bone in a situation when it's unsupervised.
And of course, you should avoid giving your dog anything that's been treated with preservatives or other additives.