It was delightful to speak to you - it must be a very difficult time for you.
If he does have mental capacity then the forms that you need are here
There is also an overview here
and for once the fee has gone down and not up!
As I said it is worth doing both to ensure that you are able to make decision about his care as well
If the news is less good then you will need to be appointed as his Deputy
Over view here
The forms are here
I hope that this is of assistance - please ask if you need further details