Quick Vehicle Inspection
From www.about.com

To determine whether your vehicle is capable of surviving a trip off-road, do a visual inspection, making sure that the following parts are in good working condition and you don’t hear any strange noises coming from these areas:
Battery – clean terminals
Brakes – drums, rotors, pads/shoes, fluid, hoses, leaks
Belts & hoses – look for cracks or bulges
Body/frame – look for cracks
Cooling/heating system – look for leaks
Driveline/transmission – leaks, fluids, universal & cv joints, skid plates
Engine – carburetor, fuel injectors, spark plugs, wires, pcv valve, pumps
Exhaust – muffler, tailpipes
Fluids – oil, transmission, brake, radiator coolant, gear oils, wipers, power steering
Lights – headlights, brake lights, auxiliary lights; make sure they’re aimed properly
Nuts & bolts – tighten axle u-bolts, lug bolts, nuts
Suspension – springs, shocks, alignment, wheel bearings, steering linkage
Tires – air pressure, tread wear – including your spare!
Wipers – check for wear