Software engineering practitioners have information needs to support strategic, tactical and operational decision-making. However, there is scarce research on understanding which information needs exist and how they are currently fulfilled in practice. This study aims to identify the information needs, the frequency of their occurrence, the sources of information used to satisfy the needs, and the perception of practitioners regarding the usefulness of the sources currently used. For this purpose, a literature review was conducted to aggregate the current state of understanding in this area. We built on the results of the literature review and developed further insights through in-depth interviews with 17 practitioners. We further triangulated the findings from these two investigations by conducting a web-based survey (with 83 completed responses). Based on the results, we infer that information regarding product design, product architecture and requirements gathering are the most frequently faced needs. Software practitioners mostly use blogs, community forums, product documentation, and discussion with colleagues to address their information needs.