Travel tips please for my 9 day stay in Ireland.

Your itinerary needs a little work to make sense. Cork isn't a day trip from Dublin. Even if you have a car it's over a three hour drive each way, and you need to be back in Dublin for Newgrange/dinner theatre the next day. A flight would really take just about as much time, once you consider getting through security each way and all. Put your Belfast/Causeway day there instead (train to Belfast from Dublin, bus to Causeway). Do your Powerscourt/Glendalough day after Newgrange (bus tours are available to both). You could then take a bus to Kilkenny and on to Cashel the next day. If you stay in Cashel it's a straight shot south to Blarney and Cork. Limerick is about 2 hours by car from Cork. I believe there is also a train, but I rent a car when I go, so I don't know for sure. Then it's about a 4 hour bus trip or so from Limerick back to Dublin. I would say that you are better off paying as you go, since a pass would not cover tours like P/G and Newgrange. Really consider the time involved to get to each area, and what you want to see there. It doesn't seem to me that you have allowed time to actually see anything once you arrive. For example, if a bus from Cashel could get you to Blarney early in the morning, Blarney Castle has wonderful grounds to explore in addition to the castle itself. If you want to go up in the castle, there might be a waiting period involved. Across from the castle is Blarney Woollen Mills, which has great shopping. You will want to stop for lunch somewhere. Then you have less than half a day to see anything in Cork (plus the wait for another bus to get you there). You might be happier to cut out some of the moving around in order to have some actual sightseeing time.

Patty, that's a mad itinerary, here's what I'd suggest. First off, hire a car to do that 8 day tour, you'll waste half your time going/waiting for trains/busses, forget flying, as Nancy says the flight would take longer with all the faffing around Day 1 - Arrive around 1400 and bus to hotel - explore Dublin a little. Day 2 - Explore Dublin Day 3 - Giants Causeway and Belfast Day 4 - Newgrange and Dinner theater in Dublin. Day 5 - Powercourt and Glendalough Day 6 - Kilkenny Castle and Rock of Cashel Day 7 - Cork and Blarney
Day 8 – Limmerick (why Limerick?) and Cliffs of Moher

I wondered why Limerick, myself. So, John, again great minds think alike! Your itinerary and mine are exactly the same!

I neglected to write that we plan on returning to our hotel in Dublin as many nights as possible ...

If you reorder your trip the way John and I suggested, you will be able to spend your first five nights in Dublin. The rest is just not feasible to do as day trips.

You might take a look at www.irishrailtours.com. They have day tours covering most of these areas if you do not have a car. Bus Eireann,among others, does tours to Newgrange.

@Kim: I think you may want to do some more research for your 2013 Ireland trip. Specifically, distances. From Dublin to Galway is at least 3 hours each way. Galway to Doolin & the Cliffs at least 90 minutes each way (at least for my relatives who drive the backroads of Western Ireland like they are on the Indy 500 - tour buses chug along at a slower pace - and everyone comes to a standstill when some farmer is puttering along in his tractor or a flock of sheep decide to stand around on one of the narrow roads). You are talking about 9 hours of transit time for a day trip, which (unless you are there in the summer when daylight lasts longer) will give you maybe 1 hour to spend looking at the Cliffs and, if your lucky, about enough time to chug a pint in Doolin and Galway City before you run for the bus. If you can't manage at least a 1 night stay in the West to really give yourself some time to explore, you can find plenty to do nearer to Dublin. @Patty: Belfast can be done as a daytrip, but I would not recommend trying to cram it in with exploring Giants Causeway on the same day. There's enough in Belfast to fill a whole day, and the same with Giants Causeway as you'll enjoy time along the Antrim Coast especially when you add in Dunluce Castle and the rope bridge (if you are there in season). John & Nancy gave you good insight about what may make your plan a bit more doable.