Steve Smith, a spokesman for the California Labor Federation, called 2013 "a banner year for workers" in the state and said the benefits of the legislation would be felt immediately.
"California has really established itself as a national leader in terms of protecting the rights of workers, and that's exactly where we should be, in our view," he said.
In the most far-reaching move, minimum-wage earners will be paid $9 an hour starting July 1, the first of two dollar-an-hour boosts that will push the base wage to $10 by 2016, giving the state one of the nation's highest rates.
Other benefits and protections take effect Jan. 1.
Domestic workers now must be paid time-and-a-half if they work more than nine hours in a day or more than 45 hours in a week, although baby sitters are exempt from the mandate. California follows Hawaii and New York in offering certain protections to in-home caregivers.