Not sure if it's been mentioned, I skipped some pages in the middle, but a common method for making this a more manageable "DIY" chore is to break up the painting (or re-painting) to a little each year.
With our common old traditional 2-story center-hall colonials, this is most often done by painting one side of the house each year. This creates a 4-year cycle, or more often 5 - 6 years by the time you spend the odd years on an outbuilding or odd trim details.
My present carriage barn is sided in Cedar, and I just pay someone to paint the two sides that get beat by the sun every 6 years, or thereabouts. The shady side has been holding strong 10 years now, and no signs of peeling yet. I think his standard rate is around $650/day in our somewhat high rent corner of the world, but I pay less due to "old friend" discount. He always scrapes then sands all surfaces, yes even the entire side of a barn, before painting. Not sanding thru the old finish, except where it's peeling badly, but to remove any dirt or gloss.
My parents owned a house all sided in painted Mahogany, and used to have to get that house repainted every 4 - 5 years. They'd usually remove the wood shutters and do them DIY, while paying a pro to paint the siding and window exteriors.