Most of this sort of information I have documented in Google docs, this way I can share it with my wife, older kids, etc.
Maintenance and repair history for the house, appliances, vehicles, lawn equipment, finances, recipes, etc, etc.
Some examples: When I last mowed the lawn, changed the furnace air filter, changed the oil for the car, changed the oil for the lawn mower, recipe for vegetarian chili, cleaned the pump filter for the washer, etc, etc.
Our family calendar is also in Google calendar so, basically we use Google docs for all of this sort of information.
This also suddenly makes me realize my whole family depends on Google to function. That's a scary thought, lol.