Take a look around. Ask to see an empty bedroom. Ask to use a loo and check for smells.
Ask how many staff they have on overnight, how many staff vacancies they currently have, and what turnover is like. Ask to see a copy of their most recent report.
What times are mealtimes, how many staff do they have helping residents who need support to eat, what are the menus like?
What's going on during the day? Do they have an activities coordinator, who visits (library, vicar, hair dresser, podiatrist, local brownies, whoever)?
Is there a garden, and if do are any of the residents actually using it?
Listen to the tone of the staff when talking to other residents. Are they kind? Go with gut feeling.
We recently had to do this for a rellie. Had a choice of three places. One looked fab, each resident had their own large private suite, the home has a garden and keeps chickens and Guinea pigs, residents are encouraged to help grow veg etc. But there were incredibly loud radios blaring in every public area all the time.
A second, brand new, state of the art, ultra modern, excellent reputation. But talking to residents they hated the food.
So went for the third. Nothing special as far as the building is concerned. Smaller rooms, shared bathrooms. But a manager who goes above and beyond. Sherry served before Sunday lunch and for residents birthdays. Smaller; it's home not a Home.
Hope you find somewhere decent where you can know he is being well cared for.