We're getting a second dog! Some questions....

Well, I took a longer hiatus than I'd anticipated, but we're finally adopting a second puppy! He's an apparent corgi/cattle dog mix. He'll be ready to come home with us late next week!

Before we bring him home, I've been preparing and puppy-proofing and rereading my puppy books. I'm pretty comfortable with my ability to raise him properly, but there are definitely going to be some differences this time around and I'm trying to prepare myself as much as possible.

First, he's a herder. He's definitely going to be different than Molly, who's a bulldog/beagle mix. We read up on the typical traits and issues that usually go along with corgis, cattle dogs, and other similar breeds before we decided to get him, but I haven't gotten to know too many herding dogs personally. If anyone has personal advice for a new herding dog owner, it would be much appreciated!

Second, I want to be sure to NOT mess up again on the one aspect where I feel I let Molly down a little bit - socialization. We socialized her really well when she was little, then she hit adolescence and we didn't keep up with it as well, and she's still shy with strangers and in crowds. I'm going to be sure to maintain it with the new puppy, and we'll enroll him in classes which will help, but I have some concerns with his initial socialization before he's 12 weeks old.

Since Molly's not great with strangers and large groups, I don't want to bring them into my house and have to manage her issues while trying to socialize the little one. Since we get plenty of foot traffic around our house, I'm thinking I'll keep Molly inside and hang out with puppy in the yard (where she can't see us through any windows and get upset), and wait for neighbors to pass by on their walks and ask them to greet him. Would this work? Is it safe before he's fully vaccinated?

I would also like to take him into work to meet my coworkers. Dogs aren't allowed in the building, but I can take him to the small gated parking lot behind the building. Would this be unsafe without him being fully vaccinated? If we set him down on the ground at all, I have a picnic blanket with a waterproof backing that I would put him on. I feel like it would be the best possible way for me to socialize him with lots of people I know and trust, but is it too risky? Does anybody have any other suggestions for safely socializing him before he's 12 weeks old?

The last thing I'm concerned with is generally making sure Molly and the puppy get along well. I've read "The Art of Introducing Dogs" and plan to use some of the methods in that book, though the rescue is hesitant to allow us to bring Molly to meet the puppy before he's ready to be adopted. Even so, Molly's always been very patient with puppies and I'm pretty confident that we won't have issues with the initial introduction. It's sharing her home, toys, and people with him that I'm afraid she'll take issue with. She's never shown the slightest inclination to resource guarding in her life, and even willingly drops her favorite ball if she thinks one of her dog-friends wants it, but I have a nagging worry that a permanent situation might be more difficult for her. Other than making sure the puppy doesn't pester her, is there anything else we can do to make the transition from "only child" easier for her?

I appreciate any advice!