I may be writing too late for you, but thought I would post anyway. I currently live in Ireland, and have very rarely encountered a problem eating out, even in hotels. As the other posters mentioned, Ireland is one of the easiest places to travel gluten free. (Most of the problems I encounter eating out is finding gluten free food that is also vegetarian!)
Many restaurants have at least some understanding of celiac disease, and most can provide gluten free options. If you have a chance to purchase your own foods, most stores have gluten free sections, though smaller stores like Spar and Centra may have a limited enough selection.
Also, it may be worth checking out the Irish Coeliac Society, if you haven't already left for your trip. Here's their website: http://coeliac.ie/.
Hope you have a great time in Ireland!