These notes illustrate the basic elements for analysis and design of linear control systems. With 15 chapters and an appendix of 4 sections the notes start from the notion of mathematical model (system), explaining its important role in the study of a phenomenon and how linear models can arise in practice. Through the time and Laplace analysis the behaviour of a linear model is studied in detail.The basic notions of stability, steady-state and transient response and structural properties give a deep insight in the study of the behavior of an abstract model.In this first part of the notes, the emphasis has been put on the analysis of the properties of a linear system. In the second part of these notes the basic model interconnections are studied, in particular the feedback interconnection and its importance in the design of control systems. Different design methodologies (dynamics assignment, root locus, tracking and disturbance compensation) are illustrated in detail with the support of useful criteria (Nyquist criterion, Routh table) and mathematical tools. In the appendix the necessary mathematical tools are reviewed. The arguments are supported by many examples and figures.