The paper provides a detailed overview of the scientific background, mostly published in 1970s-1990s, which resulted in tremendous success in preparation of modified electrodes, later used for bioelectrochemical, (bio)catalytic, photoelectrocatalytic, and other applications. The systems overviewed in the paper are focused on the chemisorption of sulfur-containing molecules (thiols, disulfides, sulfides, etc.). The self-assembling of these molecules at various metal (mostly Au and Pt) electrodes resulted in the formation of the well-structured monolayers, which allowed unique chemical and electrochemical features, not achievable by other modification techniques. Notably, the present paper is different from other typical reviews and books about chemically modified electrodes-it is not aimed at highlighting the recent achievements in the research area, but provides a detailed analysis of the area background produced about 30-50 years ago. While there are many reviews on the present state-of-the-art (mostly describing specific applications), the background of the research area is not well remembered, particularly by young researchers and students. Therefore, the paper is mainly aimed at educational aspects, rather than highlighting the modern applications, which are only briefly mentioned in the concluding section. The chemical structures exemplified in the paper represent a comprehensive collection of the systems produced by the self-assembling method developed a few decades ago.