When you cast your votes for President and Vice-President every four years, you are actually voting for your candidates' electors. You are actually voting for John Smith not George Bush and Josephine Doe not Al Gore. In turn, these electors vote for the President and Vice-President.
The United States Constitution provides that electors be "chosen" every four years on the first Tuesday after the first Monday in November. Although the Constitution outlines the procedures of the electoral college, the method of choosing electors is determined by the individual states. In all states they are chosen at a general election. The number of electors for each state is equal to the number of it's Senators and Representatives in Congress. The total number of electors is 538, a total of 100 Senators, 435 Representatives plus 3 electors for the District of Columbia. Certain federal officials cannot be electors: Senators, Representatives, or "persons holding an office of trust or profit under the United States".
The United States Senate President in the presence of the Senate and House opens the certificates and counts the votes on January 6 at 1:00 p.m. The candidates receiving an absolute majority (270) of the electoral votes are declared President and Vice-President of the United States.
If no candidate for President receives a majority, the three highest vote recipients are voted on by the House. Each state has one vote and a majority is needed for election.
If no candidate for Vice-President receives a majority, the Senate votes on the two highest vote recipients.
If the President-elect dies before January 20, the Vice-President takes office.
The presidential election should be viewed as 51 separate elections for electoral votes (50 States and D.C. see map below). The key to victory is to win enough votes to total 270 (a majority of the total of 538) electoral votes. The candidate who wins the most votes in a state gets all the electoral votes of that state. Whichever party slate wins the most popular votes in the State becomes that State's Electors-so that, in effect, whichever presidential ticket gets the most popular votes in a State wins all the Electors of that State with the two exceptions of Maine and Nebraska where two Electors are chosen by statewide popular vote and the remainder by the popular vote within each Congressional district.

Spring of election year: Each political party chooses electors and alternates in each state according to the number of electors for that state. This is usually done at a state convention.