At the core of any learning process is a didactic triangle with three basic components: teacher, student and didactics. Globalization places the didactic triangle in an open learning environment. The “open” didactic triangle can be considered a conceptual tool for designing new learning models, including those for digital textbooks' use and development. These textbooks are more than digitalized versions of printed textbooks. Connected to the Internet/Intranet and with advanced technologies, digital textbooks offer more freedom for teaching, learning and assessment as well as connectivity, adaptivity, flexibility and interactivity. Moreover, digital textbooks have well-established psycho-pedagogical foundations. The post-modernism philosophy indicates at keeping good practices, namely visual instruction, audiovisual instruction, programmed instruction and computer aided instruction (assessment). This chapter emphasizes the effectiveness of good practices and concludes with a call for the future research of the best solutions in the area of digital textbooks use and development.