Britannica is an excellent general encyclopedia. It will provide concise biographies AND will provide links for additional websites for further biographical information
When searching the catalogue, and the web, it is important to consider the different names and titles a person may have. Sometimes, an individual may use a nickname or a portion of his name in his public life. In official biographies, however, he may be known by his official name. It is a good idea, during your preliminary research, to list all the names a person may be known by.
For example:
The websites of the political parties is a good place to read about the official platforms (and will often provide a different perspective on their opponent's platform).
Britannica is a good starting place to get background/historical information about the political parties. Opposing Viewpoints in Context will provide current news items. News agencies will provide specific information about the political platform in the news.
Gallup: Politics
Opinion polls conducted by the Gallup polling organization.
Poll Watch: New York Times
Public opinion polls conducted by the New York Times/CBS News.
Polling: The Washington Post
Public opinion polls conducted by The Washington Post.
Rasmussen Reports: Daily Presidential Tracking Poll
Polling data from Rasmussen, an independent polling firm
RealClearPolitics: Latest Election Polls
Aggregated polling for the Presidential, Senate, and Governor races.
OpenSecrets
Lists federal campaign contributions, campaign financial data, and lobbying data.
InfluenceExplorer
Follow fundraising in the presidential campaigns, Congressional campaigns, and Super PACs.
Factcheck.org
Independent journalists work to check the facts presented by public figures. Accuracy is determined and reported here.