In this year's 2010 U.S. election, who are the American citizens voting for? I'm not sure because I'm in Canada.

We're voting for senators and representatives at the federal level. We're voting for governors, legislators at the state level, as well as city and county officers.

What do you mean by represenatives?

We gave two branches of Congress, our law-making body. Two senators are elected from each state to the Senate. The House of Representatives is made up of many more representatives, based on the population of each state. States with a lot of people get more representatives than states with small populations.

http://bensguide.gpo.gov/3-5/government/national/legislative.html

In the 2010 U.S. election, American citizens were voting primarily for members of Congress. Every two years, all 435 seats in the House of Representatives and approximately one-third of the 100 seats in the Senate are up for election. Additionally, there may have been various state and local elections taking place, including gubernatorial races and ballot initiatives. To find specific information about the candidates and positions up for election during that year, you can refer to various sources such as news websites, official election websites, or the official websites of the political parties involved.