This is really supposed to be my diatribe and tips on how to get good photos while in Ireland. Hopefully I can shed some light on places to shoot and tips for getting good images. However, I'm certainly not a pro so your milage may vary with these tips. I found they worked pretty well for me. If you want more tips head over to photo.net's tutorial site.
It's always said that the best time to take photos is a few hours around sunrise (blecch!) and sunset. Ireland is no different. However, unless you're comfortable with Ireland driving (I mean really comfortable) I would suggest taking late day shots somewhere near the location in which you're staying. I drove after dark only once. And only for a few miles. And I didn't like it at all. Just a little too hairy for my tastes.
There is one major perk about the light in Ireland. Given the fact that the latitude is so friggin' high even when you don't take shots around sunrise or sunset you can get decent images. At Ireland's latitude the sun strikes the earth at a rather sharp angle and as a result it's not too tough to get some sidelighting detail in your landscape shots. But nothing beats sunset photos and I recommend you shoot around that time if you want stunning images. However, even shots taken at 11:30am can come out pretty well if that's what you're going for.
More tips: It's windy in Ireland. Bring that tripod and weight it down if you can. As you get closer to the coast the wind only gets stronger. Those shots at 200mm focal lengths with 1/30 sec. exposure time probably won't be as sharp as you'd like so get used to it. The wind was the bane of my existence while shooting. I did everything I could including wrapping all extraneous straps and whatnot around the tripod legs to keep them from flapping and I used the Elan IIe's mirror prefire to cut down on the vibrations from mirror slap whenever I could. I also used my infrared remote so I didn't have to touch the camera when taking shots. Every bit helps.
