GovInfo, a service of the United States Government Publishing Office (GPO), which is a Federal agency in the legislative branch. Provides free public access to official publications from all three branches of the Federal Government.
OREGON.gov -- The Oregon government home page
The Oregon Blue Book -- The official state directory and fact book about all levels of government in Oregon
USA.gov -- The U.S. government's official web portal
For much, much more, see the UO Libraries Government Information web page.
BallotPedia This "online encyclopedia of American politics and elections" covers U.S. politics and elections and the national, state, and local levels. A very useful source for information on ballot measures (including initiatives, referendums, etc.) at the state and local level.
OpenSecrets.org from the Center for Responsive Politics. "Nonpartisan, independent and nonprofit, the Center for Responsive Politics is the nation's premier research group tracking money in U.S. politics and its effect on elections and public policy."
Politics1 A guide to U.S. politics and elections information.
Sunlight Foundation A non-profit, nonpartisan organization that "uses the power of the Internet to catalyze greater government openness and transparency, and provides new tools and resources for media and citizens, alike." Information about U.S. politics and government, connections, campaign finance, and more.
Who Rules? An internet guide to power structure research A guide created by UO Sociology professor Val Burris to resources that help you trace the distribution of resources, formal and informal social networks, and much more, linking individuals, groups, and corporations to political power.
WWW Virtual Library: International Affairs Resources A well-maintained, extensive directory to resources in international relations, foreign policy, and more.