You just have to be careful about the stairs because of their knees.
Especially if your stairs are shallow, creating a steeper step. The thrust of going up them and down them, if your dog has loose knees can create a problem not only for the developing joint, but the ligaments around them.
If you go to your vet and have them access that your pups knees are tight at this point, and your pup shows interest in going up/down the stairs, then I'd say GO AHEAD, just for the first few trips have him/her on the leash and make sure they navigate the steps properly and don't barrel down them or race up them like her/his tails is on fire!
