Once you use a well seasoned cast iron pan, you will not ever want to use another pan again!! Here is how I season them.
Fill the pan half full of ground pork tallow (ask your butcher if you dont have any, it can be purchased cheap.
Cook over a very hot campfire for a few hours stirring alot and making sure the whole pan gets coated. (I do not use my household stove for this as the tallow gets very very hot and can start a fire)
I then remove from campfire, and let the tallow cool, and become gelled, after emptying the tallow, I rub the rest all over the inside of the pan.
I then remove all the soot off of the outside of the pan.
With use of the pan, it will become more and more seasoned. As others have said, NEVER use soap on the pan.
Hope this helps, and enjoy the cast iron!!!