One of the first places I learned about when I hit the ground in Ireland for my vacation was the Spar which is a convenience store similar to what you would find in the States such as a 7-11, Stewarts, etc.
They offer the typical things like soda, candy, and chips as well as a decent selection of pharmaceuticals, wine, liquor, beer, and of course, coffee and pastries.
Two things that I really liked as a tourist were their ATM (fees on a ATM are cheaper than waiting in line and paying to exchange your money from one currency to another in my experience) and the Leapfrog bus pass. Which, for a reasonable 25 euro, can get you a unlimited few days of getting around town and is a lot cheaper than parking or taking a taxi.
If you are in the area and looking for a convenience store and new to the country, just look for the pine tree logo and "Spar" name. read more