Metals on ZnO surfaces are widely applied in catalysis, gas sensing, and microelectronic fabrication. The morphology of the polar zinc-terminated (0001) and oxygen-terminated (000-1), as well as the non-polar (10-10) and (11-20) prism faces of ZnO was investigated with STM. Images of polar surfaces, prepared by sputtering and annealing at 500-750°C, show two types of terraces rotated by 60° with respect to each other. Mono-atomic steps alternate between straight and saw-toothed profiles. Increasing the annealing temperature to 800°C smoothes the surfaces but creates a higher density of small holes on the stepped terraces. A (1x3) reconstruction was observed on the ZnO (000-1) surface after annealing at 750°C. After sputtering and annealing the ZnO (10-10) surface at 550–700°C, the terraces are separated by steps running along either [000-1] (type A) or [11-20] (type B) directions. The same treatment of the ZnO (11-20) surface leads to a “wavy†surface morphology, i.e., hills (consisting of small terraces) with an average height of 80Å and a separation of 55Å. Near-atomic resolution was achieved on both non-polar faces. Cu nucleation is strongly correlated with surface defects. Cu deposited on a "freshly-annealed" ZnO (10-10) surface shows preferential nucleation of exclusively 3D islands oriented perpendicular to the atomic row direction at the step edges. When the density of impurity atoms on the terraces is high, both 2D and 3D islands are randomly distributed across the terraces. These results are compared with those obtained for growth of Cu and Pt on the other faces of ZnO. Work performed at Tulane was supported by a NSF-CAREER grant. ORNL is supported by the U.S. DOE-BES under contract No. DE-AC05-96OR22464.