The self-assembly of well-characterized, nanometer-size Au clusters into ordered monolayer arrays spanning several microns has been achieved. Techniques to insert molecular wires to link adjacent clusters in the self-assembled array have also been developed. "Unit cell" nanostructures formed from individual Au clusters supported on a self-assembled monolayer film of the double-ended thiol molecule p-xylene-alpha,alpha’- dithiol show evidence for reproducible single electron effects at room temperature when studied by scanning tunneling microscopy. From these measurements, estimates for the electrical resistance of a single molecule can be obtained. The experimental values for this resistance are in reasonable agreement with theoretical calculations using the Landauer approach.