Two or three other minor items:
Since your Dad has passed it would help to update beneficiary designations on any insurance policies.
If your Mom doesn't mind, she can put you on her checking or savings accounts as a joint owner. That way if she passes or becomes incapacitated you have instant, legal access to some of her money for doctor bills or final expenses without having to go through additional procedures to use the power of attorney, or executor paperwork.
Start a spiral notebook dedicated to the estate process, and use it for notes with dates to retain any and every bit of activity, meetings, phone calls , especially any monetary transactions in any direction. Also maintain lists of contacts and phone numbers, email addresses, etc.
This keeps everything in one place, and preserves info that you thought you would never forget, but you just might.
The monetary records are especially important if you have any siblings, so that all transactions are documented to support your actions if anything is challenged later. This helps insure fairness to all parties, especially you.
