Many dogs are timid, whether they're from a shelter or a breeder. Often it's a personality trait ingrained in their DNA while other times it's a learned behavior from their past history. Whatever the case may be I have a unique method that has gotten...
If there's one word you'll be saying more than any other when you get a new dog it's the "No" command. It's only natural for a new to not know the rules of your house. A puppy obviously knows nothing when you first get it...
A shelter dog is just as trainable as a breeder or store bought. Be sensitive to the fact that they went through a traumatic experience by being in the shelter. Be patient and let them earn your trust at their own pace....