I am a staunch supporter of and advocate for cooking on cast iron cookware. I own half a dozen pans and use them almost daily.
Cast iron cookware has been around for hundreds of years. The same reasons that made it popular 200 years ago make it popular today. It is durable, non-toxic, non-stick, heats evenly, and retains heat well.
There are styles of cast iron for almost every type of cooking. When most people think of cast iron, they think of the old black fry pan their grandmothers would use to make bacon and eggs. Though the cast iron skillet is still one of the most traditional of cast iron vessels, it isn't the only choice. There are square skillets, Dutch ovens, casserole dishes, griddles, and deep fryers. I own one, and in some cases several, of each.
There are many makes of cast iron. Wagner and Lodge are probably the two best known. It really doesn't matter which one you buy; they are all pretty much the same.
There are two main types of cast iron cookware: enameled and non-enameled. Today I will discuss only the non-enameled variety. I will say, though, the porcelain enameled variety is very good for Dutch ovens because the enamel coating prevents rust, eliminates the need for seasoning, and allows you to cook more corrosive foods, such as tomatoes.
The fist thing you have to do before you use your cast iron cookware is season it. This is the process that bonds oil into the cast iron to build the non-stick surface. Much cast iron now comes pre-seasoned. Though this is a great advancement in cast iron cookware, I would still season it again before use.
Non pre-seasoned cast iron will come from the factory light grey in color and with a thin waxy coating on it. This should be removed by scrubbing with warm water and a brush or the rough side of a sponge. Dry the cast iron and then coat the pan, inside and out, with a thin layer of vegetable shortening or lard. Place the pan in your oven at 250-300 degrees for 90 minutes. Turn off the oven and allow the iron to cool to room temperature. Remove the pan and wipe off any excess fat.