For more see the Government Information portal at Columbia.
Some useful places to begin:
Government Accountability Office (GAO) : Known as "the investigative arm of Congress" and "the congressional watchdog." GAO supports the Congress in meeting its constitutional responsibilities and helps improve the performance and accountability of the federal government for the benefit of the American people.
Department of Energy:
The Department of Energy has four distinct missions: Energy, Defense, Cleanup and Waste Management, and Science, Technology and the National Labs.