All the above advice is excellent. Here is what we did...
We made the mistake to not intoduce on neutral territorty, that didn't work out to well, Our Lab hated our male puppy, then upon researching how to introduce a new pup into the family. We re introduced on neutral territory with both dogs on a leach, and in the house Harley, the lab was queen constant praise ect so that she knew she was alpha dog. And she still is, the pup is almost 8 months and he still tries to challenge her but she always wins in the end
. Oh we also kept all toys away until for a day so that Harley wouldn't freak if the pup took a toy. Now they get along great, Harley loves the company, and Dilbert sticks to her like glue.
Good Luck I am sure everything will be fine
Nina