How to Restore and Maintain a Cast-Iron Pan
How to remove rust from your cast-iron pan:
To remove rust, scrub your pan with a steel wool scouring pad and a little warm water (you can also use coarse salt if you don't have steel wool on hand or need additional abrasiveness).
Wash well with warm water (and a mild dish soap if desired).
Dry well immediately! NEVER leave any water on a cast-iron pan.
How to "season" your cast-iron pan:
First, using a paper towel, coat the pan with a neutral oil like canola or vegetable oil (including the bottom and handle of the pan).
Then bake upside down in the oven at 350 degrees F for 1 hour (line the rack below with foil to catch any oil drips). This will protect the surface and give it an almost nonstick quality.
Turn off the oven and let the pan cool in the oven before touching.
How to maintain your cast-iron pan in the future:
Whenever you use your cast-iron pan, just rinse it with warm water--don't use soap--and make sure to dry it really well (wipe it out or set it over low heat for a while). This will keep it seasoned and prevent rusting.
The more you use the pan, the more seasoned it gets and the better it works!