It's election day: Here are some things to know before hitting the polls

Billy "Ironman" Collier fills out his ballot on May 1 during primary elections in the gym at East Ridge City Hall.

View our 2018 Voter Guide

Voting gets underway Thursday in Tennessee for the county general election and state and federal primary contests. Big this year are the races to fill the state's top leadership position and a Senate seat in Washington, D.C. Other contests for the state House also have gained regional and national attention.

Here's what you need to know before hitting the polls.

RACES TO WATCH

» Tennessee governor: Leading Republican candidates to succeed term-limited Republican Gov. Bill Haslam are U.S. Rep. Diane Black of Gallatin, Knoxville entrepreneur and former state economic commissioner Randy Boyd, state House Speaker Beth Harwell of Nashville, and Williamson County businessman Bill Lee. On the Democratic side are former Nashville Mayor Karl Dean and state House Minority Leader Craig Fitzhugh of Ripley.

» U.S.