Using simple examples from everyday life, an Einstein scholar offers entertaining, nontechnical demonstrations of the meaning of relativity theory. Starting with the geometrical and cosmological ideas of the ancient Greeks, he traces the theory's development from its basis in work by Kepler, Galileo, Newton, Faraday, Maxwell, and others. 1983 edition.
Here's a sample of other books in this Dover category
The Great Physicists from Galileo to Einstein by George Gamow The distinguished scientist and author traces the development of physics from the age of the ancient Greeks to modern particle physics, offering fascinating biographical and historical data. 136 illustrations.
Beyond Geometry: Classic Papers from Riemann to Einstein by Peter Pesic This is the only English-language collection of these 8 accessible essays. They trace seminal ideas about the foundations of geometry that led to Einstein's general theory of relativity.
The Universe and Dr. Einstein by Lincoln Barnett "The main ideas of the theory of relativity are extremely well presented," declared Albert Einstein in his foreword to this clear and readable exposition. 1957 edition.
Elements of Relativity Theory by D. F. Lawden The basic concepts of relativity theory are conveyed through worked and unworked examples in this text, which requires only elementary algebra and emphasizes physical principles and concepts. 1985 edition.
Readable Relativity by Clement V. Durell Concise and practical, this text sketches the mathematical background essential to understanding relativity theory. Each subject is illustrated with diagrams, formulas, and examples, plus exercises and solutions. 1960 edition.