the inside it what you want to "recondition" as that is the part where the food comes in contact with...
if memory serves me correctly
1. lightly scrub the inside of the cast iron with warm water and 0000 steel wool. do NOT use brillo with any chemicals or what not. if the cast iron is in rough shape, it is ok to use a TINY bit of soap first time around, rinse thoroughly, and then do again with just 0000 steel wool
2. coat the inside of the pan with oil... any high temp oil is good from what i recall. i have walnut oil which is good to 450 or 500 I believe.
3. place the pan upside down in the oven and keep it in there for 30 min or so... place some aluminum foil on rack below for any of the oil that will drip out.