The essay examines which competencies a public librarian needs to work with literature promotion of fiction for adults and how these competencies are obtained. The purpose of the essay is to shed light on the work of promoting literature and the skills that are considered valuable for the implementation and to identify the prerequisites for this skill acquisition. The study is an interview study and we have collected the material through qualitative semi-structured interviews. The study contains interviews with five librarians who all work or have worked actively with literature promotion. Jean Lave and Etienne Wenger's theories of situated and social learning are the theoretical framework through which we have analyzed the results. They believe that competences are mainly acquired in a community of practice by being in the context in which the work is to be carried out and through the social interaction that takes place there. We have particularly focused on the three dimensions; mutual engagement, joint enterprise and a shared repertoire. The result identifies several competencies around the work of literature promotion, of which knowledge of literature and social competence are the most prominent. In our conclusions, we can state that the informants obtain competencies through formal education, in their own free time and in a joint practice. When the informants describe the ways in which they obtain competencies for the work of literature promotion, the situated and social learning emerges as significant. Learning through communities of practice is given a high value as the informants stress the importance of forums for social interaction and exchange of experience as important learning opportunities. With the help of the theory, it also emerges that learning through a community of practice does not happen automatically but requires certain conditions that a workplace organization may or may not favor.