Use the Egan Library catalog to find books about the history and development of political parties, voting, and other aspects of US elections.
Find magazine, newspaper, and journal articles about the candidates and elections using these library resources.
Bias may certainly be present in articles as well as web sources. Check the document Both Sides of the Story, by the Thomas G. Carpenter Library at the University of North Florida, if you are unsure of the political leanings of a specific publication. You can also check the publication's website as well.
Keep current with what's happening with the candidates, issues, polls, and election progress through various media.