I'm getting a new dog, so whats the best way to introduce it to my current dog?

We have a Blue healer/Border collie shes about 4 and were getting a Schnauzer/yorkie shes small and just got spayed thursday. Lizzie (our current dog) gets along well with other dogs and is extremely hyper. Jojo (new dog) is fairly calm and scared, she came from a dog farm and has had 3 litters of puppies and wasn't treated well. But does get along with other animals. How is the BEST way to introduce them?