Measures on gay rights and child abuse are among the top state laws taking effect as 2013 begins.
Voter-approved laws allowing same-sex couples to marry take effect in Maryland in January and in Maine on Saturday.
California also approved a law exempting clergy members opposed to gay marriage from performing same-sex marriage ceremonies.
California is also banning a medically discredited form of psychotherapy aimed at making gay teenagers straight, but the law is on hold during a court challenge.
A number of laws seek to protect children from bullying and abuse.
Pennsylvania school employees in contact with children must now be trained to recognize warning signs and know their legal obligations.