Open Secrets 
Open Secrets is your guide to the Money in U.S Elections. Here you can find out how much financial backing the different candidates have in the race to get elected.
At last count Bush was at $228,743,338 and Kerry raised $186,593,248. You can also see how much each candidate has spent.
Click on “Candidate Comparison” to see who some of the big contributors are. Did you know that Microsoft employees gave $51,122 to Howard Dean? Or that $16,766,578 was donated to Bush from retired people while Kerry only received half that from them? How about this…both Kerry and Edwards have Lawyers as their top contributors.
You can also check out the candidates from The Senate and the House. Choose by the state you are curious about and you’ll get facts in a nice chart where everything is laid out in front of you by district.
This site also outlines where the money goes in elections, and is real step by step help to understanding it all. Let me tell you, I was confused at first, but this site lays it all out for you making it easy to understand and make some sense of all the figures.