I spent a while in Ireland, working at a cement plant, and one thing I noticed is how disturbingly american parts of ireland have become. That said, the whole country was freakin awesome, and I reccommend staying on the northern and western parts, which are a bit less populated than the west coast, and are truly a sight to behold. The irish airline AerLingus usually has good package deals for flights/car rentals/B&B stays. B&Bs are the way to go, stay away from the hotels, not only because of how touristy hotels tend to be, but the folks who run B&Bs are usually really friendly and will help you out with directions to the best sights and pubs.
One part that I'd say is a "must see" is the city of Galway and the Aran islands. Galway is an old fishing city on the west coast, and famous for its live music and seafood... best fish & chips I've had in my life (at a place called McDunnahs)... and over the time I was in ireland I ate ALOT of fish & chips... From there you can take tours to the south of the Burren and cliffs of moher, to the north of Connemara, and get ferries to the Aran Islands. But be warned, some places americans aren't loved as much as you'd think. During one night at a pub listening to a local band sing irish songs, some american tourists requested "Danny Boy" and the band basically told them to fuck off... priceless.
But yeah, those are my two cents, and if you've got any questions just pm me... when I was living there I was working in Drogheda, a small farming town north of Dublin, and the other workers at the cement plant showed me some great local bars where farmers get together during the week, get drunk and jam out and sing irish ditties... so yeah, good luck, regardless of what you end up doing ireland is a hard place not to enjoy.