This paper explores how newcomers experience their transition to work as they strive to move from a position of "educational" knowledge to professional knowing. Hence, we focus on how newcomers learn to transform knowledge to knowing at work. We do this through the analysis of two ethnographic case studies: one with a focus on new office workers and the other on newly employed paramedics. In our analysis, we approach knowledge as a question of knowing through practise. This enables us to recognize the complexities of learning at and for work and learning and knowing as integrated processes, where learning is situated, relational and mediated. We find that newcomers' learning occurs through social interactions and participation, not simply by joining in but involving complex interactions to first find and grasp the pathways or the "codes" (established organizational culture) that enable fruitful participation. Getting access to colleagues and thus, established practice is already considered important support for newcomers to learn to enact "educational" knowledge professionally. However, we find that what is most important for newcomers is how they become knowledgeable as they recognize that it is not their educational knowledge, but working out how to engage and participate in the social practices, that counts.