I'm not sure if this is the best advice out there, but here's what we did with our little Ellie.
Have the two meet on neutral ground. Someplace away from your house and yard. Maybe down the street or around the corner, wherever is convenient. Let them sniff and greet one another. Then, take them on a brief walk. Your new puppy will probably need a potty break after the drive, anyway, so this will help her to go. Then you can walk them back home and get her set up in whatever room you want to keep her in while she explores. Most people use the kitchen or bathroom since messes are easier to clean up. Once she has had a chance to explore and maybe get some food/water, you can do some supervised Tess and puppy time. And I'm sure you can take it from there. :)
Congratulations! That's always so much fun! As far as greeting, growing up we just brought them home. Hah, I know "dog whisperer" types would disagree but heck, tha'ts just how we did it. Supervised of course, but if you ask me, it's a dog, yes you want them to get along but it's probably not always going to happen like magic in the first 5 seconds.
When my Mom and I went to pick out her new puppy, we brought my dog Buddha along to the breeder's home and her corgi pack. They got along fine and he got a chance to get her smell down and have I'm sure a conversation or two by the time we got home.
This was of course nearly 6 years ago and she runs the roost around here!