Fly, don't drive.
Check into a nice B'n'B and ask where the "local" is (that's the neighborhood pub), then strike up a conversation with the natives and you're all set.
Personally, I enjoyed the far west: Galway and the Aran Islands; also Clare and Sligo. I also especially liked Donegal, it's very wild, and the resort towns there Bundoran and some others. Ride the trains, talk with the people.
There are castles all over the place, including the Rock of Cashel which I have not seen yet but it's near my ancestral town in Tipperary.
O'Ping!
DO NOT kiss the Blarney stone. A friend from college (Irish boy from that area) told me it is somewhat of a local custom to get drunk and go late at night and piss on the sacred stone, then laugh at the thought of tourists kissing it.
Don't plan on riding trains or buses unless you're willing to wait a while.
Don't picnic in completely deserted public parks in Dublin.
(Sorry I couldn't think of any "do's"..)
Can you provide a few more details about what you like to do?
Also, have you been a lurker? FR isn't exactly the site you sign up for and ask for travel advice on the same day.
When you get back to the US, read this book:
If you read it before you go, you won't get it. But once you've been there, you will be rolling on the floor laughing.
The natives speak the language! ;-)
I am born, bred, reared and living in this country. Tell me what you want to find out, what your hobbies are, what you like to experience...I'll help you.
But you aren't giving us much to go on.
good choice for a vacation! Ireland is a gorgeous and friendly country. My advice is to not spend much time in Dublin, especially if you will not be in Ireland long. Dublin has its charms, but as far as European cities go, it's just not that spectacular. If you are a big James Joyce fan or have some other strong interest in seeing Dublin, by all means go for it. But otherwise, IMO your time is better spent seeing the west of Ireland. In fact, you can even fly directly to western Ireland on AerLingus (on a kelly green plane too!). AerLingus offers direct flights from a few US destinations into Shannon Int'l Airport, which is very close to Limerick and about a two hour and very scenic drive from Galway. I don't know how the prices compare though to flying into Dublin. When I visited Ireland, we actually took British Airways from Chicago to London and then an AerLingus connecting flight to Shannon.
Yes, take me with you!
Don't leave it to October - it's one of our coldest months, come now! We're having one of the best summers in years.
The stores have signs saying "Beware of Pickpockets" for a reason.
Also, it may appear at first that there are a lot of caravan park in this country - but they are actually tinker camps!
My great-grandmother-on my father's side-hailed from Galway originally.
Drink a Guinness for me. Where I work at the moment Guinness costs $6 a can.
:(
Do go to the north! Everyone will always tell you to do the west. And they are right - it is beautiful and fun. But that's what every American tourist in Ireland does. And the establishments there cater to that. If you go to the north, you will face less tourists and get more of a chance to see the "real Ireland."
Do go to Derry and the murals. Go to the north coast and see Giant's Causeway. If you play golf try to play Royal Portrush, but bring plenty of balls. Absolutely positively do a Black Taxi tour in Belfast. It is a must. Even my boyfriend, who is from the north was very impressed and informed by it. You can book them at the Europa hotel, where they happily tell you its the most bombed hotel in Europe. Don't worry, though it's been ages since it was bombed.
On the west coast, Galway is the best. Its easy for day trips in Connemara, and has great nightlife. Be weary of Eyre Square at night though. Salt Hill is a nice place to stay in Galway. If you're interested in hearing trad music, most of the pubs on Qauy street play some in the late afternoon, evening. Again, its usually geared toward American tourists, but the locals enjoy it too.
If you make it down to Dingle, stop in the South Pole Inn, in Anascoul. Very cool pub opened by one Tom Crean upon his retirement from multiple expeditions to the South Pole with both Scott and Shackelton. I believe they do walking tours from there if you're into that sort of thing.
In Westport, Co Mayo there is a pub called Matt Malloy's (as in the Chieftans). Try to befriend a local around there any you might get lucky enough to be a part of a lock in, where they play great live music until all hours of the night.
Do allow plenty of time for driving from place to place, especially on the west coast. It may be a small country, but so are the roads and it can take a lot longer to get from point A to point B then you would think.