I am trying to find books on different mythical and scared places of Ireland. The ones i have found have only talked about the main the ones that i aleady know about. I was trying find a book that talked more about the ones of the beaten trail.
Two that I have and can recommend are Mythic Ireland by Michael Dames and Early Ireland A Field Guide by Anthony Weir. I am not sure if they are still in print. You could try Alibris, Amazon UK, Irish Books & Media or Kenny's. The Shell Guide to Ireland revised and updated by Peter Harbison is good but also includes castles and other things.
I presume you meant sacred places. The scared places are any road that I happen to be driving on.
Try Standing Stones to Stormont by Tom Kumpf. Amazon has it. It covers a variety of well known and not so well known and it really recounts personal experiences and speaks to the mystical aspect of Ireland and it's people. The photos are beautiful and the writing is quite nice. I can't say that it is exactly what you are looking for, but I can say that it is a book that you will be glad you own.
The author lives in my hometown (or near it) and I have had the opportunity to see his work displayed locally.