General grooming advice for pups:
1. Clip the little tuft of hair at the end of the pup's tail. Perhaps an old wives' tale, but many people feel that allowing the wispy hair at the end of the a pup's tail will cause him to start holding his tail slightly higher up. Thereby lending to a higher held tail which is against the breed standard and is a negative in conformation. Some pups will also drag this wispy tail into mud, urine, and stools so it's probably cleaner to remove this hair as well :)
From the USCA German Shepherd standard:
"The tail extends at least to the hock, but not beyond the middle of the hind pastern. It has slightly longer hair on the underside and is carried hanging downward in a gentle curve, whereby in a state of excitement and in motion it is raised and carried higher, but not beyond the horizontal. Operative corrections are forbidden. "
2. Your puppy might be itchier than normal in the next couple of months. They will be going through a couple of coat changes so sometimes when new hair follicles come in, it can cause irritation and itching. Think of your leg or facial hair coming back in after waxing or shaving for example. It will sometimes cause itching as the follicles push through the skin. So just keep in mind before considering allergies and other issues.
3. Be sure to clean your pups ears regularly. Also keep nails trimmed and short. Long nails are a nuisance and hazard so keep on top of them. Even if a puppy fusses, he will get over it. They were all clipped at least once a week and are used to it - along with the dremel as well. Don't give in to overly whiny displays. It only encourages the aversive behaviors and plays right into what the pup wants - you can be sure to expect an even more exaggerated display with each time you give in.
The zymox products work well.
4. If you have a male pup, very carefully trim the hair at the end of his penis. This hair tends to hold urine and bacteria which can cause urinary tract infections (UTI). Do this super carefully or have your vet do it for you.
5. Don't allow people to pet your pup on his head. This tends to cause puppies to drop their ears back and down. For one, it works against the ear cartilage when we are trying to encourage ears to come up. And two, you don't want your dog to excessively drop his ears as an adult whenever someone approaches because they are so used to being petted on the head. Pet/scratch his chest, back, or tummy. Avoid touching his ears too much or going for that area first upon meeting.
6. I have never bothered brushing any of my dogs' teeth. Just give your pup a few good chewies throughout the week. Acceptable items include bully sticks or braids, raw knuckle bones, or deer/elk antlers. If you feed a raw diet, you likely won't have any issue with dirty teeth.