See the Library's elections exhibit in the Feldman Center (C building) lobby
New York City registration information (NYC Board of Elections)
Although you can register any time during the year, your form must be delivered or mailed at least 25 days before the next election for it to be effective for that election.
Special note for students
New York State Board of Elections
Applications must be postmarked no later than October 12th and received by a board of elections no later than October 17th to be eligible to vote in the General Election.
Connecticut Mail-in Voter Registration Form
Your application must be postmarked or received by a voter registration agency by the 14th day before an election or you may register in person with your Registrar of Voters by the 7th day before an election
Pennsylvania Voter Registration Application.
In order to vote at the next election, this application must be received by your county voter registration office 30 days before the election, or postmarked no later than the thirtieth day before the election.
The official PA voter information website (may not load properly in some browsers)
Special information for college students