I have two lists to contribute.
My beloved and I have a file we call The Plane Crash File.
If one of us were to die in a plane crash, what accounts have what passwords, the benefits Guy's phone #, where is the money, etc.
Obviously all of the sensitive info in one place is scary, so we keep it locked up, and update it 4 times per year.
The other checklist I created is how to do a training. First I created a mind map on the topic, and from there came the list.