Digital data are now widely recognized as valuable assets -- research resources that have tremendous potential for reuse in new and innovative ways. As recognized by Jim Gray over a decade ago, and the natural history community decades earlier, realizing this potential will require ready access to extensive bodies of curated research data. Advances in the management and archiving of digital data are proceeding apace, but curation services need to extend to identification of high-value data and enhancement of data to fit new purposes. Through our studies of data practices across more than a dozen sub-disciplines in the earth and life sciences, and associated data representation and identity problems, we are uncovering indicators of reuse value and conditions of fit. I will present key research outcomes that are directly informing data curation education and practice and discuss our next phase of work leveraging strategic collaborations with scientists, data centers, and repository developers: the Site-Based Data Curation project, with geobiologists and resource managers at Yellowstone National Park, and the Data Curation Education in Research Centers partnership with the National Center for Atmospheric Research.