What do i do to introduce a new puppy to an older dog?

[Mitch]

Hello.
So i've been looking to adopt a new dog into the family. Recently(October) we lost the dog's sister to a stomach tumor. Now she has been depressed and generally runs around the yard looking for her sister.
She hasn't been getting enough exercise and has gained quite an amount of weight.

It's been lonely in the house without her sister(we also have a cat as well) and we were just wondering how we could get a new puppy. We're interested in adopting a local Siberian Husky pup.
Our current dog is a Lab/Chow mix. How should we go about doing this? She's also a Female and we plan on adopting another Female.