Buy the book, which includes photos and descriptions of breeds. Try to find similar to your dog. If you like this photo not found, do not despair. Try using a broader search on the Internet. Comparing my dog and pictures, remember that they may differ in color, it's not always the representatives of a species have a certain color.
Can walk with a pet in the big parks where I walk and other breeders of their animals. Talk to them, maybe they know what breed your dog. But if they start to assure you that it is not the breed, not the fact that they are right. And whether it is so important to the breed and pedigree, because the animal you love, probably not for this.
If the desire to know the breed and does not leave you, go to the dog handler or the veterinarian. Be sure to identify the breed can experienced person who engaged in dogs and their breeding. By a veterinarian is also possible to try to clarify, but not always a doctor can precisely tell about the breed of the animal.