What should I do to a car that has not been run for years?

I'm buying a van from my uncle(87 Ford econoline 250).
He has not driven it in years, the windows have so much gunk on them you can't see out of them, the tires are flat, but the paint is okay(it was under a carport). If it does not run I will still buy it but charge offer him less money.
I'm probably going to get the battery charged(at advance-auto for free), clean corrosion of cables, change oil; then I will see if it starts up. It has only been sitting for like 2 years, so no need to spin the oil pump. Possibly some starting spray, carb-cleaner, or gas in carburetor, but I have never used that before.
What other precautions should I take when trying to start a vehicle that has been sitting?
Thank you

BTW: there's an auto junkyard several miles away from me, they charge 50 dollars for an all-you-can-carry-on-your-back special, so I might be able to find some good parts to help start or fix the vehicle there, including tires(just put rope through the tire rims and carry them easily!).

Added (1). Who knows, the van might start right up. Still have to change all fluids, and gas, battery.

I love those junkyards and you have a popular car.
Well, you're in for some work but the great thing is she'll run. Pull out all the plugs and use sandpaper on the contacts. I'd go for a simple tuneup, rather cheap. Plugs, wires, engine oil and tranny oil change, filters on gas, tranny, engine, air and oil breather on the valve covers. New pcv valve as well. Buy some seafoam and run it dowon the throttle body or i your case carburetor. Once you clean the plugs. It will do what 10 over the counter carburetor cleaners will do.

Don't use starting fluid that would damage the engine, and has precaution before you put the sparks plus pour in the cylinders just a little of miracle oil to lubricate the rings before you start the engine.

http://ricksfreeautorepairadvice.com/store-a-car-long-term/