Eire 90
Image by bogman

There are the Jack Roberts booklets (review at http://www.megalithomania.com/show/review/27) as well as the Kenneth McNally tome, Standing Stones and Monuments of Early Ireland:
http://www.amazon.co.uk/exec/obidos/ASIN/0862812011/qid=1092075624/sr=1-1/ref=sr_1_8_1/026-3457825-3290844

both of which I used effectively during my Cork trip.

Thanks for that - it was a trip to the Cork area that inspired my interest; can't even remember exactly where it was now but we stumbled upon a spectacular stone circle in the middle of nowhere and there didn't seem to be any information about it anywhere around (except for Lonely Planet which didn't say much). Lovely part of the world, though.