Department of Enterprise and Labour
This is a very important Department where you can source information on legislation covering many aspects of employment. possibly the most relevent area for workers is the employment rights and industrial relations division http://www.entemp.ie/employment/index.htm
THE NATIONAL EMPLOYMENT RIGHTS AUTHORITY
The National Employment Rights Authority (NERA) was established under the Social Partnership Agreement "Towards 2016" to achieve a national culture of employment rights compliance.
NERA provides information to employees and employers through its http://www.employmentrights.ie/en/information unit, monitors employment conditions through its labour inspectorate and can enforce compliance and seek redress.
NERA’s covers many aspects of employment rights including Wages, Annual Leave, Working Hours, Redundancy, Dismissal, and Notice.