The first thing I do with them is gut the inside and restore it first, then move to the outside. I can usually restore the interior for under $200, this incvludes tinting the windows, adding bucket seats, carpet(standard not molded, I cut and sew it to form), dash cover, steering wheel cover and floor mats.

Basic outside restoration would be, the breaks, the steering linkages(tie rod ends, idler arm, the upper and lower ball joints, repack the wheel bearings, shocks, steering stabilizer(if you have one), change the differentials/transfer-case/transmission gear oil, complete tune-up(new timing chain, water pump, spark plugs and spark plug wires, cap and rotor, oil change, new air filter and adjust the valves). You don't have to change all of these things if you know for sure they have been recently changed, but if the truck has been sitting for a long period of time, or was never serviced regularly a lot of these items could still be the originals.