I buy a small moleskine notebook for every house we've bought, that becomes the 'house book'. Major appliance purchases, dates and serial numbers. A 'local' copy of the circuit breakers. Renovations with dates, costs. Room diagrams with measurements.

But also things like the paint codes and finishes for every room, trim, ceilings, etc. That really comes in handy when you have to do a drywall repair or something and the only can you have left, the paint has slopped over the label.

I also had a separate notebook for The Move and The Purchase. It had all the contacts - mortgage lending officer, realtors, inspectors; appointments, vendors, dates of major events; move-in punch list, move-out punch list, inventory with what to keep, what to toss, what to donate. Expenditures, documents to drop off at which municipal offices along with addresses and phone numbers.

It's really empowering to have all that information literally at your fingertips.