Hi, I'm brand new too - actually you're ahead of me, as we plan on getting our first chicks in the spring. So, I'll also be interested to read the answers to your questions.
As regards your dog - I, too, have a dog that is going to need some training to leave chickens alone. We have been working extra hard on teaching "leave it," with lots of treats to reward him. To keep dogs from digging, we have had pretty good luck with securing wire fencing flat on the ground horizontally the way CTKen describes - it isn't just the physical barrier, they seem to really hate the way it feels on their paws. Once they give up, we can usually take it down.
Welcome fellow newbie