University of Michigan Documents Center - is likely the best single source of government information of all types. "The Documents Center is a central reference and referral point for government information, whether local, state, federal, foreign or international. Its web pages are a reference and instructional tool for government, political science, statistical data, and news."
Firstgov.gov - "The U.S. Governments Official Web Portal"
U.S. Government Documents: Subject Guide and Internet Resources - courtesy of the Lehman Social Sciences Library at Columbia University. "Hot Docs" (documents in the news) is particularly useful for finding government documents relating to issues currently being debated by Congress or discussed in the media
GPO (Government Printing Office) Access - "The U.S. Government Printing Office disseminates official information from all three branches of the Federal Government."
United Nations Documentation: A Research Guide - while not technically government information, "this guide is designed for researchers and information professionals with an interest in United Nations documentation. It presents an overview of the various types of documents and publications issued by the Organization (e.g, reports, resolutions, meeting records, sales publications, press releases) and gives guidance on how to work with them."
The United States Code - Courtesy of the Office of Law Revision Counsel - "The Office of the Law Revision Counsel prepares and publishes the United States Code, which is a consolidation and codification by subject matter of the general and permanent laws of the United States."
Code of Federal Regulations - "The Code of Federal Regulations (CFR) is the codification of the general and permanent rules published in the Federal Register by the executive departments and agencies of the Federal Government. It is divided into 50 titles that represent broad areas subject to Federal regulation. Each volume of the CFR is updated once each calendar year and is issued on a quarterly basis."
The Federal Register - "Published by the Office of the Federal Register, National Archives and Records Administration (NARA), the Federal Register is the official daily publication for rules, proposed rules, and notices of Federal agencies and organizations, as well as executive orders and other presidential documents"
Stateline.org: your source for state news - designed to help journalists and others interested in the functioning of state governments around the country. "Our purpose with...this guide is to save time by organizing information resources available to reporters, particularly reporters who cover topics like education, healthcare and welfare reform." Courtesy of the Pew Center on the States, a research project of the University of Richmond
Congressional Research Reports from Open CRS - "American taxpayers spend nearly $100 million a year to fund the Congressional Research Service, a "think tank" that provides reports to members of Congress on a variety of topics relevant to current political events. Yet, these reports are not made available to the public in a way that they can be easily obtained. A project of the Center for Democracy & Technology through the cooperation of several organizations and collectors of CRS Reports, Open CRS provides citizens access to CRS Reports already in the public domain and encourages Congress to provide public access to all CRS Reports"