Election Research: Subject Guide: Election Schedules & Info.

"Elections occur in every even-numbered year for some federal and most state and local government offices in the United States.

Some states and local jurisdictions hold elections in odd-numbered years.

Thus,

• Every four years, Americans elect a president and vice president.
• Every two years, Americans elect all 435 members of the U.S. House of Representatives and approximately one-third of the 100 members of the U.S. Senate. Senators serve staggered terms of six years each."  

More: from U.S. Elections in Brief

Estimates of the voting-age population for all 50 states (from the U.S. Census).

"Every two years, Georgia voters elect members of the legislature. These elections occur in even-numbered years (e.g., 2008, 2010, 2012). The qualifications for holding office in both houses, as well as the size of both chambers, are established in the Georgia state constitution."

"All elections in Georgia are overseen by the Elections Division of the secretary of state's office. County registrars perform the duties of registering voters and conducting elections at the local level. In several smaller counties this function is handled by the judge of the probate court. At the state level it is the secretary of state's responsibility to tabulate official returns and certify the outcome, thus pronouncing a candidate duly elected to office."

More from the The New Georgia Encyclopedia

Estimate of the voting age population for Georgia (from the U.S. Census).

• Primaries and Caucuses: Primary elections are one method by which a political party nominates candidates for the next general election for congressional, state, and local offices. The main difference between a caucus and a primary is that a caucus involves face-to-face interaction between voters to act on official business, and to try to persuade one another to vote for (or against) a certain candidate.
• General Elections: The purpose of the general election is to elect the winner from the field of nominated candidates. General elections have the most offices and issues on the ballot and usually generate more interest and higher turnout than any other election.
• Special Elections: A special election is held when someone who is already in office can no longer serve and must be replaced. All registered voters in the district can vote in a special election.