1 word for books, videos, podcasts, speeches, etc. (learning materials)

One of the senses of content is a pretty close match.

1.4 Information made available by a website or other electronic medium.
        ‘online content providers’
_Lexico

From a different source (which expands content beyond online mediums):

In publishing, art, and communication, content is the information and experiences that are directed toward an end-user or audience. ... Content can be delivered via many different media including the Internet, cinema, television, radio, smartphones, audio CDs, books, e-books, magazines, and live events, such as speeches, conferences, and stage performances.
_Wikipedia