From their web site:

"Smith County, Mississippi and Its Families, 1833-2003" is now available. Copies of the book can be purchased from the Smith County Genealogical Society for 40.00 + $5.00 shipping. Request and payment can be sent to:
Smith County Genealogical Society, P.O. Box 356, Raleigh, MS 39153. Be sure to indicate that payment is for the "Smith County, Mississippi and Its Families, 1823-2003" publication.