Chuck, you've asked one of the most caring and compassionate questions I've ever heard.
My best advice is:
- Make sure that all bank accounts, credit cards, investments, real estate, vehicles, etc are in jointly in both your names. An iron-clad will is great, but money (and things) can still get tied up in legal red tape and due process; instead, make sure that your wife has immediate access when she needs it by giving her indesputable access to it now.
- Put all important documents (will, deeds, titles, insurance, bankbooks, etc) in a single envelope and let your wife know where it is
- If you can, pay off all your debts now. If you have insurance which you intend to be used to pay off debts, leave clear instructions on what insurance is to be used to pay off those debts and insert that in your envelope
- Plan your funeral as best you can. Your wife will be devastated when you pass and will be faced with dozens of (relatively meaningless) questions about flowers, clothes, music, coffin and headstone styles and colours, lists of people to invite and so on. You may want to consider pre-paying all the expenses with a funeral home and making these plans with them.
- Write your own obituary. A friend of mine did this before she passed and it was one of the most beautiful celebrations of life that I've ever read.
- Assemble items for your eulogy. A simple book containing your favourite memories, pictures, cards - what's meaningful to you. Give your family a rich source of inspiration as they write your eulogy.
Most importantly:
- Write several love letters for your wife and seal them to be opened after you've passed
- Dum vivmus, vivamus! (While we live, let us live!) Enjoy life!