What is the role for the House of Representatives and the Senate in impeachment?
The House chooses what charges, known as articles of impeachment, the president should be tried for. If the House chooses to charge the president at all, he is considered impeached. The Senate hears the trial on those articles and votes on whether the president is guilty or not guilty. The chief justice of the supreme court oversees the trial in the Senate, but has no power other than keeping order, calling on lawyers, etc. The president will be forced from office if the Senate finds him guilty. A 2/3 majority vote in the Senate is required to find guilt. See http://jurist.law.pitt.edu/rules.htm .
