If you are looking at one of the foreclosed home that is put on here by RealtyTrac, it does not mean it is for sale. If there is no address on the listing this is most likely the case. All it means is that the home is in some state of default. It may never come on the market, and nobody knows at what price if it does.
My advice is it work with a buyer's agent. They will let you know what is available to purchase and they will guide you through the process. If you need help finding someone, let us know.