The Electoral College is a process, not a place. The founding fathers established it in the Constitution as a compromise between election of the President by a vote in Congress and election of the President by a popular vote of qualified citizens. The Electoral College page on the National Archives website is an excellent resource to learn more about presidential elections.
A pamphlet has been compiled and published by the Office of the Federal Register, National Archives and Records Administration, for use by the Executives and Electors of the several States in the performance of their duties in connection with Presidential Elections.