LOS ANGELES -- Immigrants who may qualify for protection from deportation under the president's executive orders should immediately begin gathering documents, from birth certificates to utility bills, that will help them prove eligibility, advocacy groups are advising.

"We do expect millions of people will benefit and millions of lives will change in a very profound and positive way,'' Arnulfo De La Cruz, director of Mi Familia Vota California, a non-profit advocacy group, says of President Obama's announcement Thursday.