Want to know when an initiative becomes law? Voters in Ohio had a number of ballot initiatives to consider yesterday. For those that were successful, the state Constitution outlines the process by which they become law. The short answer is in Article II, §1b of the Ohio State Constitution:
"Any proposed law or amendment to the constitution submitted to the electors as provided in section 1a and section 1b, if approved by a majority of the electors voting thereon, shall take effect thirty days after the election at which it was approved and shall be published by the secretary of state."
You might also want to look at Chapter 3519 of the Ohio Revised Code for additional laws relating to initiatives and elections.
The initiatives on Ohio's ballot passed through the Ohio Attorney General's office as well as the Ohio Secretary of State. The Secretary of State's Web site has advisories, directives, and other information relating to elections, including procedures for getting an initiative or referendum on the ballot. The Attorney General reviews the submissions, and you can see both approved and rejected ballot initiatives.