Do you have any no-kill shelters by you? Or a local ASPCA? If I can't do anything to help a cat or dog, I usually call one of them. I don't trust the Humane Society as far as I can throw them!
For other animals, we have a Wildcare Center that's really good about helping. I brought an injured duck over there once and they were able to fix him up and re-introduce him to the wild!