A good baby gate would be first on my list.
Next if this was my first pup, I would start checking out dog training classes and ask about upcoming puppy classes. Explain that you are waiting to receive your puppy and would like to sit in on a class session so you can get an idea of her class structure, etc.
Next, I would call all of my friends and relatives in the area and get everyone's imput about the local vets and where the nearest emergency vet is located. You do not have to approve of the emergency vet, just know where they are. But for your own vet, it is best to find someone you like and trust.
Next, I would find a dog club in the area, or a GS club. Start going to meetings, maybe find out about puppy matches. Once you have your puppy, and it has a couple of sets of shots, taking it to puppy matches is a great idea. For one thing, this is not a dog park free for all. Most of the people at puppy matches are at least a little more dog-savy than your average dog park clientel. Not saying there aren't good people at a dog park, but on any given day, you can have any idiot do any number of insane things. Puppy matches and obedience and rally runthroughs have the dogs on lead, unless they are advanced and in the ring, and tons of people who know and care about dogs there.
Now that you have your baby gate, your trainer, your vet, and your support group/socialization group, a crate of an appropriate size or a grow with me type crate, stainless steel water and food bowls, hard rubber toys, squeaky toys, soft toys, and bones for chewing, a martingale collar and a lead, and a long line would be the essentials before the pup came home.
If your yard is not fenced, you may consider creating a fenced in area for your pup, a small area where you can open the back door into it is nice so you do not have to leash the pup to take it out there. Also having some area fenced makes a great place to play with the pup with outside toys, or to relax with your pup and not having to be constantly vigilent as you will need to be inside.
Good luck with your pup. Waiting is hard, isn't it. There is plenty of things to do to prepare though. You could spend the ENTIRE time researching dog foods and ingredients and becoming a nutricianist. I would not suggest it. You could find the absolute best food out there only to find your pup doesn't care for it. Still, there is no time like the present to choose a few brands and varieties of dog food for your new pup.