I just want to add a comment or two to the good answer Scott gave, address another of Sarah's comments, and add a suggestion.
Sheriff's Sales are really for fairly sophisticated investors. You will be on your own, and really need good knowledge of property values. Also, there is a two year redemption period during which the former owner can redeem the property, albeit they do have to pay a fairly stiff interest rate.
You do not have to bid sight unseen. A notice listing the properties coming up for auction is posted at the county court house, and you can often call to get the list. Some counties also provide the info online.
If you are interested in buying a home, you are better off finding a REALTOR to help you find a decent foreclosure, better off yet if you find a short sale, and significant numbers of sellers are selling at foreclosure level prices these days. Short sales are usually in better condition than foreclosed properties, and sell for about the same. The advantage of buying a drastically reduced home is that you may just be able to get an even better deal, including seller contributions to your closing costs--plus a seller's disclosure of property condition, which you will not get on a foreclosure.... more