What a great idea. I have a few suggestions, based on both my experience as an English as a Second Language tutor, and as a newcomer to two foreign countries (where my husband was assigned). Italy, the Veneto region, was very cultured and fairly easy to adapt to, but the island of Curacao was a whole other story.
If the family will be using the laundromat, provide them with a couple of rolls of quarters, or tokens or whatever the nearest laundromat requires.
If you have an idea of what local schools the kids will attend, find out what the school supply list looked like at the beginning of the year (notebooks, pencils, flash drives, Kleenex, whatever else middle schools or high schools require these days) and give each kid either a bag of supplies or a basic backpack containing the essentials to head off to school with. Will the girls need locks for their lockers or are they the kind that just need a number combination (the school would handle that, but if they need locks, you might supply them).
Provide him with a list of the utility companies (gas, electric, water) and their phone numbers (both the set-up numbers and emergency numbers).
Find out about the school lunch system. Do kids in the girls' grades bring lunch, or buy it? How do they buy it? Be prepared to explain it to your friend.
And see if the schools have some kind of parent portal for registering, checking on grades, reporting an absence, paying for lunches, etc, and provide the website to the family (and perhaps explain the system).
When we lived on Curacao, I wish that someone had explained to me where to buy things the kids were always needing for school projects. I was accustomed to being able to go to Hobby Lobby, or Office Max, for poster boards, display boards, etc, but the system was totally different there and I was so lost. Who would have looked for highlighters and pens and markers at the store that sold small electric appliances? Not me. But that's where I found them. So you might provide them with the name of a local store that most of the students find basic supplies at - it could be a very different system from what they're used to.
Make a list (maybe on a white board, or a laminated piece of paper) of important addresses and phone numbers to post at their home, in case they need assistance when your friend is working and not available. Pharmacy, doctor, police, water department, etc. I needed that in Curacao, and I felt safer knowing my kids could refer to the list if necessary.
Provide a list of important federal or state holidays like President's Day, Patriot's Day (in Massachusetts), etc, when banks and post offices will be closed.
That's all I can think of. I'm so glad your friend's family will have this welcome when they arrive!
