Service Oriented Architectures (SOA) represent a recent proposal to obtain cooperation and interoperability in distributed computing environments. A challenge of SOA is services and resources discovery which can be realized both in centralized and distributed way. The distributed approach involves peer-to-peer (P2P) infrastructures supporting the knowledge distribution among peers. In this paper we propose DNK-WSD, a new network architecture providing an efficient distributed web service and resource discovery mechanism based on the notification pattern. The DNK network is a peer-to-peer architecture built using the Distributed Network Knowledge (DNK) heuristic which represents a lightweight approach to model graphs mapping logical P2P overlay networks. A case study, regarding the deployment of DNK-WSD for information sharing in real time collaborative web applications, demonstrates the validity of DNK-WSD in terms of fast propagation of the shared data, low network load and reliability.