GSD's are highly intelligent, and thrive on human contact. If you don't make your GSD a part of the family, you will not have a well-behaved GSD. Do talk to your dog, do pat, hug and show approval, do make most of the house dog-friendly, do expect your GSD to come into the bathroom and bedroom when you're in there, do have as much interaction with the GSD as possible. A bored GSD can be destructive. Donot crate a GSD for more than 4-6 hours at a time. Do expect your dog to lick you, you're the leader of the pack, and your GSD shows deference to you in this manner!
It is extremely important to socialize your new GSD, regardless of age. After you've given them a week or two to settle in to their new home, take your dog with you as often as you can. Trips to buy pet food, hiking, the park (ALWAYS ON LEASH!), family gatherings, and quick errands to any store that will allow your dog access. Teach others to always ask permission before petting your dog. Some dog are more social than others and there is no rule that says they must allow strangers to pet them. As long as they're well behaved in public, that's all you need to ask of them. We do not recommend "dog parks" as a way of socializing your dog.