Digital technologies for identifying and linking to resources on the internet promise to make connections between scholarly publications and their underlying data more transparent and traceable. "Data citations" are formal citations included in reference lists of published articles to data resources that led to a given research result. The workshop "Bridging Data Lifecycles: Tracking Data Use via Data Citations," held by the University Corporation for Atmospheric Research (UCAR) in April, 2012, brought together 80 people from 30+ organizations to discuss many aspects of data citations. This report outlines the important activities, tools, challenges, and impediments to data citation initiatives that were identified during the workshop. The report also outlines a set of recommendations on how to get started on the processes of assigning citations and actionable identifiers to data sets without having solved every issue. By making it easy for users, providing openness and transparency in how data citation tools are being applied, and leveraging the interest and expertise of the multiple communities of stakeholders, organizations can promote, enable, and embed data citations as regular components of the scholarly communication infrastructure.