The state Department of Education on Thursday began seeking 500 veteran teachers now, and another 2,000 later, to work with aspiring teachers as part of Louisiana's overhaul of how teachers are prepared for the classroom.

The teachers will undergo training so they can serve as mentors for educators during year-long residencies in classrooms.

The new rules were approved by the state Board of Elementary and Secondary Education on a 6-5 vote last year amid controversy, including concerns about the costs of the program.

The mentors have to be nominated by their school systems by Sept. 8.

They will start training in the fall – nine sessions – at one of two locations in south or north Louisiana.

The instruction is designed to show the veterans how to work with their younger counterparts, identify and address the needs of the aspiring teachers and track their progress.

The first wave of training will extend through the 2017-18 school year and include 500 candidates.

Another 1,000 will be trained during the 2018-19 school year and the final 1,000 during the 2019-20 academic calendar.

The new rules for students who want to be teachers take effect in July 2018.

All teacher preparation programs will then include year-long classroom residencies, which will be roughly double what students do now.

The changes stem largely from complaints that young teachers were not prepared when they entered the classroom for the first time. It was pushed by state Superintendent of Education John White with support from a wide range of groups that back public school changes.

Gov. John Bel Edwards' office urged BESE to delay the push last October because of cost concerns.

A variety of traditional public school organizations, including teacher unions and the Louisiana School Boards Association, opposed the overhaul.

White has said the program can be done for $7.5 million for the first three years and that funding sources have been identified.

A $67 million federal grant is also expected to help the effort.

Mentors are expected to be paid about $1,000 per year and teacher candidates $2,000 annually.

The training is being financed by the state.

It is being handled by the The Charles A. Dana Center at the University of Texas at Austin and others after proposals were submitted to state officials.

"When done well, teacher mentoring can even lead to the mentored surpassing the accomplishments of their mentors," David Sovde, the center's Director of K-12 Education Strategy, Policy and Services said in a statement.

"Classroom teachers prepare the next generation of our students for the challenges of a competitive, ever-changing world," Louisiana Commissioner of Higher Education Joseph Rallo said, also in a statement.

Follow Will Sentell on Twitter, @WillSentell.