Brianpop has great information about the election and the presidency. http://www.brainpop.com/elections/
PBS Kids has information on voting, the president's responsibilites, and the election. http://pbskids.org/democracy/
Scholastic is a super resource on the election. http://teacher.scholastic.com/scholasticnews/indepth/election2008.htm
Time for Kids also has some good things to check out for the election. http://www.timeforkids.com/TFK/election08/