Hi there
When you get here,stand by and brace yourself for the perfectly normal aviating,despite what Mr.Flute might have implied.There are plenty of airfields but only a few have Avgas.Kilrush,Co.Kildare is a good place to start,as is Waterford.It is best if you phone up in advance(the Fly in Ireland guide is well out of date)so nip down to the library and see if they have Irish phone books.Kilkenny is another nice field.The welcome can vary,depending on the humour of some of the airfield owner/operators,who can be as changeable as the weather.
Above all,have a flexible attitude,keep an eye to the weather and you'll do fine.
regards
TDD