Reports are intended for non-expert audiences who have some knowledge on a given topic. They can also be referred to as "grey literature", which describes materials published outside of the traditional publishing processes used in journalism and academics. You'll want to evaluate their biases and check their credibility as you would any other source.
Full-text, authoritative reports and analysis on major policy issues from the CRS, a non-partisan body of the U.S. legislative branch that provides research on topics of interest to Congress. Also contains current information on appropriations bills and the Congressional budget process.
Full-text public policy documents from think tanks, NGOs, and research organizations.
A key way to locate data is to brainstorm "who else would be interested in my topic?". Often, government agencies, other academics or researchers, and interest groups or non-governmental organizations are good places to locate data.
Archive of research in the social and behavioral sciences, with collections of data in education, aging, criminal justice, substance abuse, terrorism, social media, and other fields. Includes a bibliography of publications related to data.
Data and statistics from many geographic areas around the world on a variety of topics including demographics, finance, criminal justice, education, energy, and more. You can create and download your own charts and graphs, and download data in a variety of formats.