Developing innovative products and services benefits from collaboration within multidisciplinary design teams. Design teams gather and generate large quantities of data, including user research, information on competing products and applicable technologies, and new design ideas; however, teams often struggle to synthesize this diverse design information. Collaboration can break down if they cannot form a shared understanding of the design problem. This dissertation examines current design practices to construct theoretical models of the design process and to develop new tools to help design teams create, communicate, and collaborate. It explores how information tools are used to support collaborative design processes, and suggests forms for future tools. It presents a series of qualitative research studies, i.e., survey and interviews with professional and student designers as well as observations of face-to-face student design team meetings. The analysis of surveys and interviews with professional designers offer a descriptive characterization of how design teams use technology to share information with each other in practice. These studies also inform a new conceptual framework--the sharing spiral-- that describes how information is shared throughout individual and collaborative design tasks, across user research and conceptual design phases. With this new framework guiding qualitative analysis of observations of face-to-face student design team meetings, nine challenges to information sharing are identified. This dissertation proposes design guidelines for new design collaboration technology, based on these challenges. Finally, it applies these guidelines to a new system, Dazzle. Dazzle is an information sharing tool for face-to-face design teams that allows teammates to share, log, and annotate shared design resources. This dissertation offers a new understanding of information sharing in design practice, and has implications for improving design practice and the development of future design tools.