Make sure they are micro chipped...the rest of the advice above is right on.
I will add that we had to train our dogs to stop at the door, we always go first
mainly because you don't always know what is out there and secondly you are the one in control.
Before the door is opened...leash them, if they aren't going train them to stay back. We just tell ours to go lay down, "you are not going right now"
It's all repetition and training, they will get but you have to be diligent and aware.
We got our RV so we didn't have to leave our pups home, they love it and I can't imagine spending much time away from them.
Sher