Unfortunately there is no real local brewing or micro brewing industry in Ireland.
Draft is quite limited and favours big global brands.
There are 3 stouts ... Guinness being the main one
Then Beamish & Murphy's from Cork both with less than 10%, combined, of the Irish stout market. Beamish may be available in Dingle and is lighter and a bit sweeter than Guinness.
Smithwicks is a red ale which to me is fairly bland but okay.
Bulmers (a very most popular drink in Ireland) is a fairly sweet cider and available on Draft but the majority of the indigenous population

buy it in pint bottles. It is a tradition to get your pint bottle and pint glass half full of ice and pour away yourself until finished. Be ware though a pint is circa 4.50 a pint bottle could cost 5.00

Don't ask why as I've no idea either
Harp is the only Irish larger I can think of and it is great for removing the lining of you stomach

I never liked it anyway and would not recomend it.
Then you have Heineken, Carlsberg, Budweiser and Miller the most common draught beers available all bewed in Ireland.
Expect to pay upto 3.50 for Stout (Beamish can be about 3.00 in certian pubs if available)
3.10-3.50 for shorts + 2.10-2.50 for a coke/tonic to go with it if required.
4.00-4.50 for larger (Fosters on Tap if you can find it for 3.00)
Also you will probably see very few people drinking whiskey in Ireland in the pubs unless it's a fairly old man at the bar. Also whiskey if being drunk is usually mixed with cola etc by younger drinkers. However on the plus side barstaff usually ask if you want ice or water before serving you, but don't take it for granted if the pub is very busy. Expect what ever small glass that comes to hand to used to serve your dram. Of course they will obligue you if you point out a glass of your own preference if you happen to see one.
Standard fare in the whiskey line in pubs is Paddy, Powers, Jameson, Blackbush & Bushmills regular (Circa 3.40a shot). After that it depends on the pub but Jameson 12yo Bushmills 10yo & Bushmills 16yo will be available in many pubs as will Midelton VR but expect to pay through the nose for that. And if you are very lucky there might be a few more.
One last thing if you want water and arealso ordering other drink don't be afraid to ask for a glass of tap water. It is perfectly okay to drink and saves you 2.50 on the bottles kind.
Any further questions feel free to ask.