This text, a companion to Electronic Structure and Chemical Bonding (World Scientific, 1996), is concerned with the teaching of optical spectroscopies of electronic absorption. It is the culmination of about ten years’ experience in the teaching of the subject and the training of students to become teachers in the physical sciences. The book covers topics of research and includes about 30 problems with solutions, most of which are adapted from tests. It provides as much coverage of elementary quantum mechanics, group theory and the electronic structure of molecules as is necessary for the reader to understand the rest of the topics. Also included are numerous appendices, often presented as charts to facilitate assimilation, as well as short bibliographies, limited to basic books and review articles.