The first part of this manuscript deals with fundamental theories behind surface enhanced resonant Raman spectroscopy (SERRS). Optical absorption, resonant Raman and surface enhanced Raman spectra of chromophores bound to small isolated spherical gold or silver nanoparticles in colloidal solutions are collected, presented and SERRS excitation profiles are constructed. The goal of this project is to devise a chromophore-nanoparticle system such that chromophores bind to the nanoparticles but do not aggregate them. The spectra of such a system are analyzed to give clues about two enhancement mechanisms of SERRS-- a chemical enhancement mechanism and an electromagnetic one. In the second part of this manuscript, influences of metal nanoparticles on components of an organic polymer solar cell based on poly(3-hexylthiophene)/ (6,6)-phenyl-C61-butyric acid methyl ester active layer and poly(3,4-ethylenedioxy-thiophene):polystyrene-sulfonate supporting layer are studied. Different kinds of metal nanoparticles, such as silver and gold nanospheres, silver and gold nano-sputtered films, and silver nanoprisms, are incorporated in different geometries around the organic polymer layers and resulting extinction and surface enhanced Raman spectra are studied to give clues of possible solar efficiency enhancement mechanisms achieved by the nanoparticle incorporation.