Socialising puppy with kid

I'm an experienced dog owner, and have had dogs all my life. However, our last dog died when my daughter was just 2. Now she's 5 and we have the opportunity to adopt a sweet 4mo mongrel boy. My husband has a few reservations but is slowly coming round, my main concern is that I've never had a young, untrained dog and a child at the same time. Aside from the obvious never leaving the dog and the child alone together, does anyone have any advice? My daughter is already very good at approaching dogs gently, but obviously having a puppy in the house is another kettle of fish entirely. Should we get a crated area to make sure the dog has a place to retreat and ban our kid from entering there? Anything else? Sorry if a lot of this seems obvious but I want to make sure this goes safely for all concerned and I want to avoid having to re-home a dog because of my own inexperience. Thank you!