As the first of two volumes, fundamentals of radio astronomy: observational methods is designed for undergraduate physics majors with no prior knowledge of astronomy. It explains the instrumentation and observational methods needed to make successful observations in radio astronomy. With examples interspersed throughout and problems at the end of each chapter, the textbook trains students so that they can contribute to a radio astronomy research team. The book starts with a review of the relevant astronomy basics and then discusses radiation physics, the radio telescope detection process, important aspects of radio telescopes, and how to make successful observations. It finishes with two chapters on interferometry. A set of complementary labs is provided online.