Ballotpedia - The Encyclopedia of American Politics "is the online encyclopedia of American politics and elections. Our goal is to inform people about politics by providing accurate and objective information about politics at all levels of government."
Wikipedia List of states provide generally good summaries for states with links to sources
Book of the States - Council of State Governments annual publication on the status of the branches of state governments.
Access World News includes a variety of news publications worldwide. These sources include major national and international newspapers, as well as local and regional titles as well as newswires, blogs, web-only content, videos, journals, magazines, transcripts and more.