I'd start by purchasing a chilton or haynes manuals from your local part store. (full of info). Start with the engine area. How does it run? Does it smoke or burn oil? You may want to tune it up, plugs, wires, cap, rotor, air and fuel filter, pcv. Are there any leaks around valve covers? Carb may need to be rebuilt or cleaned. Check belts and hoses. You may want to go all out and have it rebuilt if its in the budget. How does the tranny shift? What color is fluid? If he's restoring it mechanically, new brakes, master cylinder/booster, brake hoses, wheel cylinders should also be looked at or replaced. Check condition of driveshaft u-joints, they may be worn out. Check condition of shocks, tie rods, steering stabilizer, they may need to be replaced as well. I'm sure that i'm forgetting somthing but this should be a start.