It is not possible to sweat from the tongue. Instead, when a dog pants it is simply salivating. When the wind meets the saliva there is a cooling effect. Human sweat glands span the entire body. This is not the case for dogs. Instead, dog sweat glands are located in their paws. Paw pads, to be more specific, help regulate a dog's body temperature the same way human skin works.
No, a dog does not sweat through its nose. It is nothing out of the ordinary for a dog to have a wet nose. The normal state of a canine nose is somewhere in between clammy and dank. That's mucus! Mucus helps smells stick to the nose and helps dogs with their sense of smell.