Cast iron is a lovely cooking surface, and you already have plenty of advice about seasoning. I'll refrain from piling on.
The element that is missing from almost all conversation about cast iron has to do with heat conductivity. If you look it up, and Google makes this easy, cast iron has significantly lower heat conductivity than other common cookware (copper and aluminum primarily). What this means is, if you do not have a very diffuse heat source, such as an oven, or a large gas burner, or (as was common when cast iron was king) a camp fire, you will suffer from hot spots. And cold spots.
My practice when using my cast griddle is to preheat it in the oven first, then move it to the stove top when it's time to make the pancakes. Substitute "your cookware" for griddle and "your food" for pancakes in the previous sentence, and you'll be golden.