We present here a work done within the Mind the Gap European project. Mind the Gap is focused on understanding and bridging the gaps preventing the development of inquiry in science classes. One of the aspects of the project has been the study of online resources, designed for supporting IBST, or having a potential to support it. The target audience, for these resources, can be students, teachers, or teacher trainers. Analyses of resources have been developed; they have grounded the elaboration of guidelines for the design of IBST-oriented online resources. We present here: - examples of analyses, concerning two online resources: PEGASE, a resource designed in France for teachers and teachers trainers in physics; and VITEN, designed at Oslo University. These analyses study on one hand the content proposed by the resource, the adequacy of the content and of its presentation with IBST, and on the other hand the scaffolding offered to students and teachers, especially for the articulation of empirical evidence and conceptual aspects; - a synthesis of the guidelines for design. These guidelines encompass recommendations for the content of the resources, for their use in class or in professional development programs, and for the design processes themselves.