For some excellent advice on how to handle noisy neighbors with or without a barking dog, including the anonymous letter approach, click here:
How to Handle Noisy Neighbors and Their Barking Dogs
If you are a victim of irresponsible dog owners with barking dogs, visit BarkingDogs.net
If you live in Monroe/Union County, NC also see Ordinances and Local Contacts
If you are in a position (e.g., judge, magistrate, law enforcement, city council, county commissioner, etc.) to put an end to nuisance dog barking or to enforce noise nuisance laws but don't view the problem as serious, click here: Why Exposure to Chronic Dog Barking is So Profoundly Debilitating and here: The Deleterious Effect of Exposing People to Noise