blended learning environment is considered as a pedagogical system, which includes goals, content, methods, forms and outcomes of learning process. Subjects of professional competences development are a student and a teacher. The author focuses on the educational content as a complex of open sources and electronic resources of corporate access. Forms and methods of this files application to blended learning are discussed in the context of the Electronic Learning Methodology development (D.Simens, S. Downs, J. Shulman, P. Mishra, M. Kohler, T. Reevs, T. Noskova) and the Digital Humanities (J. Lanier). As an empirical example of theoretical part of the paper, there are following electronic resources (1) digital materials of St. Petersburg State University blended learning portal, (2) the portal of the Virtual Branch of Russian State Museum and corporate access resources (mediateka), and (3) the courses of "Coursera".