Highly organized monolayers can be obtained by the spontaneous self-assembly, under atmospheric conditions, of molecules in a process termed two-dimensional crystallization. The imaging of these adsorbates with submolecular resolution is possible with scanning tunneling microscopy (STM) which allows for an exquisitely detailed understanding of their arrangement and constitution.  We combine molecular design, surface science, and computation to develop a detailed understanding of these supramolecular assemblies. Use of this knowledge in the design of structurally more complex layers will allow control of surface properties (oxidation, corrosion, hydrophobicity, etc.) and correlation of these bulk properties with organization at the molecular level.