If you're looking for government publications on a policy topic, spend some time poking around the relevant agency websites. You can also try a more general portal like USA.gov, which can point you to information on a topic regardless of what agency produced it.
CQ's Encyclopedia of American Government is a resource that provides answers to the full range of questions that students, government professionals, interested citizens, and other researchers have about the institutions of U.S. government. Based on the new editions of the CQ Press American Government A to Zseries, CQ Encyclopedia of American Government (EAG) offers thousands of concise, up-to-date explanations of the who, how, and why of American democracy.
The CQ Electronic Library is made up of nine separate databases - CQ Researcher, a complete source for in-depth analysis reporting on the most current and controversial issues of the day, CQ Encyclopedia of American Government provides up-to-date explanations of the who, how, and why of American democracy, CQ Public Affairs Collection includes primary source documents, statistical overviews, contact information and in-depth reporting on current affairs, CQ Supreme Court Collection blends historical analysis with timely updates and expert commentary of Supreme Court decisions, biographies of Supreme Court justices, Supreme Court institutional history, and the U.S. Constitution, CQ Voting and Elections Collection integrates a wealth of data, authoritative analyses, concise explanations, and historical material to help researchers investigate and understand voting and elections in America, and CQ Historic Documents Series Online Edition collects more than 2,500 primary sources covering current events around the world from 1972 to present and provides a clear, logical organization and tools for exploring these rich resources.
Here is a list of various organizations promoting transparency in government as a basic tenet of democracy: