Wanting to move to Ireland. Please Help

Hey everyone. I've searched around the boards a bit and not found an awnser to some of my question sand was hopeing someone could help me out. I'm a welder/ heavy equipment operator by trade and am looking for something new. I've been thinking about moveing out of Canada to work and Ireland seems to be what i ahve made up my mind apon. I was just woundering if anyone could give me some advice on how to get the whole thing rolling. I will be takeing my girlfriend and 2 year old son with me as well. Her grandparents and great grandparents where all born in Ireland and i was woundering if that would help any in getting visa's and such. We have the proof in documentation of there citizenship as well. Any advice on finding work and moveing a family would be great. Especialy if anyone can give me some advice on where to look for a job in the construction trades in Ireland as i am haveing no luck.
Alex