Edge computing is a recent paradigm where network nodes are placed close to the end users, at the edge of the network. Efficient management of resources within this configuration is crucial due to scarcity and geographical spreading of edge resources. We begin by a brief description of the edge paradigm, the most generic edge architecture, and the terminology associated to it. Then, we propose and elaborate on a preliminary taxonomy for edge resource management, together with a substantial review of works in the area. Finally, we identify some research challenges.