Cast iron cookware is not used much anymore. It's heavy and can be hard to maintain if not properly seasoned. Many people will see rust on the cookware and toss it in fear of ingesting the rust, but when the cookware is seasoned correctly and well maintained, it will last forever and rust will not be a problem. Your food will not stick to the pans and you won't have to worry about the non-stick chemicals that are on the cookware today. You may even find you like the flavor of your food better as time goes on.
If you have new cast iron cookware, you will need to season it very well before you start to use it. Start by heating your oven to 250 degrees. Then coat the cookware with lard or bacon fat. Vegetable oils or spray-on oils are not suitable for this process. Place the pan in the oven for 10 to 15 minutes and then take it back out. Pour off any fat that has liquefied and stick the pan back in the oven for at least 2 hours. When you take the pan out allow it to cool and repeat the process. You should repeat this process 3 or 4 times over the course of a few days and then start using it to cook fatty foods to further season it. Do this with each piece of cast iron cookware you purchase.
Sometimes the seasoning wears off after many uses. Or you may have acquired some cast iron cookware that was not seasoned correctly the first time. In these instances, the cookware will need to be re-seasoned. But before you start the process it will need a thorough cleaning.
Heat the pan to a temperature where you can still handle it. Put it in hot water and use a scouring pad to clean off any residue or rust that you see on the pan. Rinse it off well and dry it immediately. Then season the pan in the same manner as seasoning with a new pan. You may only need to repeat the process once if the original seasoning was not totally worn away.
Cast iron cookware, when properly seasoned is non-stick. But because it is natural the acid in the food can break down the seasoning. Therefore, you should not let leftover food sit in the pan, in fact, it should be washed while it is still warm. You should not use anything but hot water on the pans, if possible. Scouring will scratch the seasoning and just like other non-stick pans, your food will begin to stick.
These pans should be stored in a well ventilated area without the lids on them. Too much humidity will cause them to rust and once you have rust they will need to be re-seasoned. Once your cast iron has been properly seasoned they are very easy to take care of.