Love cast iron! Yeah cure it anyway even if you got it used. Use paper towel to rub oil all over inside, just enough to make it wet with oil, then bake it about 20 min at about 375. Might smoke a little, so run the fan. The more oil you use, the more smoke, so less is better, but it does have to be coated.
NEVER use soap to clean it and in fact use a separate sponge that you never use with soap so the sponge doesn't have any soap in it either. Soap will ruin your pan!! So definitely be careful to keep soap away from it.
Cast iron actually cleans very easy if you cure it first, and always store it with a light film of oil on it. I use Pam olive oil spray, but you could use any oil, just needs a very light film on it.
I make anything in it. Anything you would fry, you can make in the cast iron pan. It's best when you preheat the pan so it is hot when you put stuff in it.
A great way to make steak is to preheat the pan and the oven to 350, chop some fat off the steak and drop it in the pan to melt and spread it around, then sear steak on both sides 3 min or so. Stick pan in oven to finish for 5 min or so if you like it medium.
Edit: Austin beat me to it!! DOH!