The resource discovery problem poses new challenges in infrastructure-less wireless networks. Due to the highly dynamic nature of these networks and their bandwidth and energy constraints, there is a pressing need for energy-aware communicationefficient resource discovery protocols. This chapter provides an overview of several approaches to resource discovery, discussing their suitability for classes of wireless networks. The approaches discussed in this chapter include flooding-based approaches, hierarchical cluster-based and dominating set schemes, and hybrid loose hierarchy architectures. Furthermore, the chapter provides a detailed case study on the design, evaluation and analysis of an energy-efficient resource discovery protocol based on hybrid loose hierarchy and utilizing the concept of ‘contacts’.