Electing people to public office requires effectively matching key ingredients - candidates, volunteers, finance, literature and messages, etc. No one ever gets aelected working alone. Some research indicates less than 10% of the eligible voters get involved in election campaigns, yet that level of involvement matters a great deal to the success of a candidacy. Whether donating funds, volunteering, writing letters to local papers, or even posting yard signs all contribute to successful elections. Websites below offer some guidance and some sources of useful information.
Federal Election Commission - search or download data of contributions and expenditures for all federal races by contributor, PAC, or candidate.
National Institute on Money in State Politics - Tracks contributions and expenditures for candidates, PACs, committees, ballot measures, and independent expenditures for each state. Easy to use tool allows you to type in your street address to identify your districts of state representation.
OpenSecrets.org : Analyzes campaign finance filings in every imaginable way: by political party, zip code, state, individual donor, industry, and more. Although the front-page emphasis is federal, state-level data is available for more than half of the nation as well. The states with coverage are shown in green on the map under the Get Local! tab. The site offers profiles of state representatives, of political parties and their committees, and of the top individual donors in the current (or most recent) election.