This is part of the “world magic” series. It tried to boil down the history of Paganism and ancient religions in Ireland. It’s not too terribly different of a book than you’ll find elsewhere, but it does have an Irish bent and covers the ideas well and un-demandingly. It’s not strictly a “how-to” book. Still, it’s a very basic Wiccan book. (Wicca comes from Witta meaning “wise one”.)
I do like their sabbat information. There are a lot of drool-worthy recipies in it, including one for honey mead. There is an excellent index of Irish gods and goddesses. All in all, not bad, if fairly basic. It’s well-made for the solitary practitioner, but does include some coven-work and parenting ideas.