If you want to buy a foreclosure and want to find one that is for sale, tHe majority of foreclosed homes eventually get listed by realtors who are hired by banks to market these properties. So your best bet to find foreclosed homes that are listed FOR SALE is by working with a realtor.
But if you want to see foreclosed homes --- regardless of whether they are already listed for sale or not -- you can go to the County records, research the list. Foreclosures are recorded on the county books.
You can also attempt to bid during the trustee sales held at the county courthouse steps --- but be prepared to bid against seasoned investors. Also be aware of the pitfalls of buying at an auction, regardless of whether they're held at the county courthouse or by an auction house.