The puppy years are always the hardest. The cute little face, the ears, the head tilt are all so cute. They all also make it extremely hard to punish or discipline that cute little face. The best way to live through puppyhood is consistency use the same punishment for the same wrong doing every time. Also keeping the same rules everyday no matter how hard it is to enforce. If your pup is not aloud on the furniture today, they are not aloud on the furniture tomorrow.
Also a schedule to keep everything at the same time everyday. Feeding time at the same time every day, then bathroom, then play time, then nap time, etc. etc. etc. remember to schedule bathroom breaks about every 2 hours to lessen the house accidents. Keep several chew toys available for them, all different hardness, and textures.
Most important of all have fun. they are only young once and they grow up so fast!!
If you have any more questions feel free to email me at Germanshepherddogs@doglover.com
I will add more to this post as I think of more to write.