Spent 2 and a half years working over there from 2016 to 2018 in Florida and South Carolina.
*edit* - Just missed out the bit about it only being a year, so take the below with a pinch of salt as it's more for living there for longer. But hope some of it helps.
Definitely get a US Bank Account and a US Credit Card. The country runs on credit and you can't even get a proper phone contract without it, but you can quickly build it up.
Get a social security number as soon as possible from the local office to where ever they will be, will require their passport and visa to get it. This will be needed to setup a Bank Account and Credit Card.
I banked with Bank of America -
https://www.bankofamerica.com - used the standard checking account for all my payments/transfer money into from the UK etc. For a credit card due to having no credit rating they will only offer them a secured credit card. I put down $500 of my own money (I think the minimum was $250) and I used that for all my daily spending and paid it off right away. After 6 months I got my $500 back into my checking account and they turned it into a $2500 standard credit card. Cheers easy.
The previous comments about the US still being way behind with regards to payments/banking etc are true. I was having to pay for my car insurance via cheque and Chip and Pin was only just being introduced in 2016. The guy at the bank even gave me a lesson on how to use it at the cash point.
As for transferring money, I used Transferwise (I think it's just called wise now) as they used the midmarket rate and not the rates the banks used (Basically I got more money after fees etc)
Mobile phone wise, I used AT+T. I initially was on a 'pre-paid' plan but paid monthly via direct debit, this included unlimited mins + texts and 20gb of Data for what was $20 (With $5 for paying via direct debit) a month. The unused data rolled over but this didn't include international minutes/data/texts etc. However I didn't change my number over on whatapp and just used that to contact home.
I used my UK phone and the AT+T sim just worked right off the bat, however 1 co-worker went with Verizon initially and it didn't work. Verizon (And the carriers they lease their network to) use different phone frequencies that are incompatible with phones from the UK. He changed to AT+T and it worked right away. It may be different now, but that was my experience.
Get a US driving licence too for ID as soon as possible, lots of places won't recognise your UK driving licence and it's just unnerving carrying your passport around all the time. The US driving test/requirements are far more relaxed than the UK, so if they have a UK one and are settled in over there they should cake walk it.
As for TV, I probably wouldn't bother and just stream stuff. Heck tell them to get a Fire Stick, put the BFBS App on it and give him your log in
Finally on Car Insurance, if they do drive over there tell them to get a 'letter of proof of insurance' (Bit like a no claims letter) when they come home. When driving back in the UK on my return, the insurance company accepted it and I had no gaps in my no claims bonus.
