My dog has bumps on the ends of her ears under her fur, they seem like crusty sores. What could this be? We haven't tried anything yet, I don't want to hurt her!

Sounds like a staph. Skin infection. Better bring the dog into the vet to get it diagnosed and treated. Maybe give the dog a bath with medicated shampoo. I am not a vet but have had lots of dogs and medicated shampoo seems to treat most skin issues. If it persists or seems like the dog is uncomfortable definitely bring it to a vet.