SIT
Show your puppy a really tasty treat and give just a little taste of it to get puppy eager. Show the treat again so that puppy will follow it with its head and try to take it. Hold the treat just above puppy's head and then move your hand back towards his/her neck so that puppy has to stretch up and lean back to reach it. Puppy will almost be in the Sit position, move your hand back just a fraction so that pup must put his/her bottom on the floor to reach up for the treat. As soon as puppy sits say "Sit" and give the treat that puppy has worked so hard for, and praise too.
After a few practices pup will understand what he/she needs to do to get the treat and it will become easier and easier. Eventually the word "Sit" will be sufficient. Say the word "Sit whenever you see the pup sitting down of his/her own accord, that way pup will learn to associate the word with the action. Ask pup to Sit before giving him/her their meal, before walking through doors, while meeting people etc.

DOWN
Put your pup in the Sit position. Show pup a treat in your hand putting it quite close to pups face, and then put your hand on the floor a little way in front of him/her, this will encourage pup to follow the treat with his head until pups head is on the floor. Make sure you hold the treat in such a way that a little bit of it is showing, but that you still have firm control of it so that pup cannot take it unless you allow. If pup breaks the Sit it isn't a disaster. Pup will try to get the treat by standing up but at the same time stooping down, and will eventually realise that to get close to the treat, he/she will have to lie down. As soon as pup does say "Down", praise pup and give the treat.
Every time you see your puppy lie down say "Down" and praise.

STAY
German Shepherds are renowned for wanting to be with their owners, so this command can be a little trickier. Just take things slowly, starting with very short stays at a close distance. It is important to teach pup that you will always come back and that there will be lots of love and affection when you do. Once this command has been mastered, you could then move on to training your pup the "Come" command from a stay. Put your puppy on a lead, put him/her in the Sit position and say the word 'Stay' while putting you arm out in front of you with your palm facing the pup. Take just one step back, wait a second, then step up to pup, give a treat and lots of praise. Gradually increase the number of steps back and the duration before returning to puppy. Once this command is understood by your puppy try putting the lead on the floor and walking around your puppy, always reminding pup to Stay. Praise & patience is the key for this command, so if pup breaks a Stay calmly put pup back into a Sit and start again. Never shout at your pup or lose your temper, remember you are the light in his/her life and it is hard for a puppy watching their owner walking away from them.

HOUSE TRAINING
German Shepherds are very intelligent dogs and learn very quickly to be clean in the house. It helps to use the same spot in the garden (or paper placed in familiar place in the house) for pup to eliminate. Take pup there every 2 hours or sooner if pup very young or still has accidents, plus: Last thing at night and first thing in the morning. Immediately after eating. Before and after exercise. After periods of excitement (playing or visitors). Whenever you see puppy sniffing the ground or circling (could be whining at the same time). When puppy is on his / her spot try to use a command word to associate with eliminating, this could be "get busy" or "do wee" etc whatever works best for you. This is so helpful if you need your dog to eliminate quickly if you have to dash out etc. When puppy eliminates praise madly, spend some time playing together before returning to the house if using the garden for house training, do not go straight back in or puppy will realise that he / she gets to stay outside longer by crossing his / her legs. Accidents do happen, and if you catch puppy in the middle of the act clap your hands to get puppy's attention and to stop him / her mid-flow and encourage him / her outside (or to the paper) in a fun / excited way. Never shout at puppy or use punishment for having an accident, pup was only answering a call of nature. If paper training, gradually move the paper nearer to the door, sometimes leaving a soiled newspaper down helps in the training process. If you take puppy out (or to the paper) regularly and are attentive to him / her, little or no accidents should happen. Good luck, and remember, this stage doesn't last long so enjoy your puppy, while they are still little.

PLAY BITING

In a pack society once puppies become active they play physical games with each other and pester their mother by pulling her ears and tail etc. In the early days puppies have licence to do what they like, but as they grow, mother and litter mates become increasingly intolerant, especially of their sharp teeth. A puppy will shriek loudly if the litter mates mouth / play bite too hard, and their mother will quickly reprimand too. When a puppy is introduced into a family this learning process is normally incomplete. The family must take over where the puppy's mother left off. How is this done?
Whenever a puppy uses its teeth in play the person concerned should respond with a sharp "NO!" and sound as if they have been really hurt. Then walk off and ignore puppy until it has become interested in something else. If this noise seems to excite rather than stop your puppy just stop interaction / play, preferably by freezing if you can, and ignore puppy until it has become interested in something else. In these ways the puppy learns to limit the strength of its bite in both play and for real and that biting is counter-productive as an attention seeking device.