Let him sniff them, receive some attention, then have it lay down and behave. Otherwise it will become one of those glory hounds that has to be the centre of attention when anyone else is in the room.
One benefit of the mix of breeds you're talking about is that it should be one smart pup. Get it plenty of toys and some that are puzzles that they have to push it a certain way to get treats and such. Finally, make sure this dog has plenty of room to run and play!!