Planning and scheduling for agents operating in heterogeneous, multi-agent environments is governed by the nature of the environment and the interactions between agents. Significant efficiency and capability gains can be attained by employing planning and scheduling mechanisms that are tailored to particular agent roles. This paper presents such a framework for a global sensor web that operates as a two-level hierarchy, where the mission level coordinates complex tasks globally and the resource level coordinates the operation of subtasks on individual sensor networks. We describe important challenges in coordinating among agents employing two different planning and scheduling methods and develop a coordination solution for this framework. Experimental results validate the benefits of employing guided, context-sensitive coordination of planning and scheduling in such sensor web systems.