When real property is directed to be sold by public sale, notice of the time and place of such sale shall be published in a legal newspaper of the county in which the estate is being administered, once each week for three successive weeks before such sale, in which notices the property ordered sold shall be described with proper certainty: PROVIDED, That where real property is located in a county other than the county in which the estate is being administered, publication shall also be made in a legal newspaper of that county. At the time and place named in such notices for the said sale, the personal representative shall proceed to sell the property upon the terms and conditions ordered by the court, and to the highest and best bidder. All sales of real estate at public sale shall be made at the front door of the courthouse of the county in which the lands are, unless the court shall by order otherwise direct.