To study "Electrical Machines," a solid foundation in several key areas is essential due to the varying prerequisites across online courses. Fundamental knowledge of physics, particularly magnetism, is crucial, alongside a strong grasp of electrical circuits to ensure safety and comprehension. Understanding AC and DC electrical theory is also vital. For those interested in design aspects, knowledge of mechanical engineering is recommended, while familiarity with basic chemistry and material sciences is beneficial for topics like oil-filled transformers. Practical experience, such as disassembling and rebuilding small electrical motors, is encouraged to enhance understanding. Recommended resources include the "Handbook of Electric Motors" for in-depth study and "Schaum's Outline of Electric Machines and Electromechanics" for a more accessible introduction to the subject.