The manual addresses three main issues: quantification of information generated by discrete sources and transmitted over discrete communication channels; optimal coding for discrete sources; noise-immune coding for discrete channels. The manual is aimed primarily at highlighting and explaining the mathematical concepts, models and results that underlie the theory, and thereby creating conditions for further independent study of its special and more complex sections and practical applications. It is assumed that the reader has the necessary knowledge of mathematical analysis, algebra, probability theory, discrete mathematics. For teachers and researchers, students and graduate students.