Any advice for transporting our new puppy home from the breeder? It will be a 3 to 4 hour drive.

Three to four hours shouldn't be too bad, about a year ago I drove 16 hours to pick up my current competition prospect puppy. I used a small airline crate and had a friend with me in case the puppy got fussy. I stopped when the pup got restless, which may have only been every 2-3 hours or so. They're all different and it's pretty normal for them to do a bit of yelling/whining at first.