This review discusses recent developments in the areas of fabrication, certain types of optical characterization, and applications of a selected class of chemically assembled nanomaterials, namely i) gold and silver nanoparticles deposited onto optically transparent glass substrates; ii) thiol-functionalized self-assembled monolayers (SAMs); iii) chemically stabilized gold and silver nanoparticles (monolayer protected clusters, MPCs); and iv) MPCs linked to metallic substrates and adsorbates. Six linear optical techniques for the characterization of these materials are discussed: transmission localized surface plasmon resonance spectroscopy, T-LSPR; propagating surface plasmon resonance spectroscopy, P-SPR; polarization-selective Fourier transform infrared reflection absorption spectroscopy, PS-FTIRRAS; polarization-modulation Fourier transform infrared reflection absortion spectroscopy, PM-FTIRRAS; surface-enhanced infrared reflection p absorption spectroscopy, SEIRRAS; and infrared ellipsometry. The review focuses particularly on providing a unified treatment of these six optical techniques by using a relatively simple stratified multilayer model.