Dubbed as the "online encyclopedia of American politics and elections," this website offers 244,371 encyclopedic articles written by professional staff, editors, researchers and writers.
Vote Smart is a nonpartisan website that offers a database with biographical information, voting record summaries, campaign finances and more for over 40,000 politicians across the U.S.
The Commission on Presidential Debates (CPD) offers access to transcripts of most presidential and vice presidential debates starting from 1960. When available, links to videos of past debates may also be found on this website.
This website offers access to data to help keep track of financial funding for lobbying and federal campaign contributions for politicians. OpenSecrets is an independent, nonpartisan and nonprofit research group that tracks political spending.
Guide to U. S. Elections by 
The Presidential Election Process by