Exercise And Play
Your puppy should not be over exercised in the first year/18mths of his life, 5 mins for every month of his life twice a day is adequate, ie; at 4 months puppy can go out for two 20min walks.
Until puppies muscles and bones have fully developed at the age of 1 year to 18 months you should discourage your dog from jumping from high places and prevent him from running up and down the stairs. Too much of this can have an adverse effect on their hip and elbow joints. A stair gate (baby gate) is very useful to stop puppy having access to the stairs.
Do not allow your dog to become overweight as this can also lead to joint damage.
Dogs love chewing and a teething puppy will chew anything they can get hold of including socks, shoes and the sofa. Buy a selection of toys for puppy to test their teeth on instead. Just make sure they are non toxic and durable and never leave puppy alone with anything that could choke them splinter in their mouth or electrocute them.
Do keep some special toys just for play with you so that your puppy will learn that you are boss of the house, as you are taking charge of play as well as food. Try to avoid chasing games as you want your dog to always run to you and not away from you. Playing tug of war with your dog is fun but make sure you win most of the time to discourage dominance in your dog.