Starting a long sitting engine.

When I bought my 1976 Pontiac Ventura, it had been sitting for 18 years. @halifaxhops covered a good part of what you will need to do, but I would add the following:

Flush the fuel system, including the tank, that means you will need to remove it to do a thorough job.
Rebuild or replace the carburetor.
Replace the fuel pump.
Replace all rubber hoses, including heater, rad, brakes, fuel.
Replace thermostat.
Inspect entire brake system, replace as necessary, plan on wheel cylinders/calipers, probably master cylinder.
Repack front wheel bearings.
Replace spark plugs, distributor cap, rotor, points (if equipped), plug wires.
Expect to find rodent habitation in the exhaust system, and interior.
Replace belt(s).
Fresh engine oil and filter, change again after 500 miles or less, be sure to add zinc additive.
Fresh transmission oil and filter.
Inspect steel fuel lines for rot.
Inspect all wiring for rodent damage.
Tires will be flat spotted, and/or dry rotted, replace all.
Inspect exhaust system for rot, muffler(s) will almost certainly be rotten.

Turning the engine by hand several times with some oil (a small amount) in each cylinder is a really good idea as well.
Following these basic steps should make it safe, and hopefully ensure the engine survives it's hibernation.