BASICS, CONTEXT, and PRO/CON from a variety of sources -- liberal, conservative, & libertarian interest groups & think tanks -- populist and scholarly:
(National Conference of State Legislatures) page with map of voter ID laws. Check it out to find out just what the states require.
: For an introduction to the issue and a summary of PROS & CONS, visit the International Debate Education Association's (IDEA) page on VOTER ID.
(National Conference of State Legislatures) page provides video and info on costs as well as pros & cons.
(National Public Radio) report on the POLITICS of voter ID laws.
(American Civil Liberties Union) opposes voter ID laws. Check out their issues page and fact sheet.
The Cato Institute
(Libertarian Think Tank) "Voter ID: A Tempest in a Teapot That Could Burn Us All"