Dan McCoy suggests the Five Best Books on Celtic Mythology over on his Norse Mythology blog. Plenty of folks are interested in both mythologies, so it makes sense that an expert in one would have credible opinions about the other.
There’s a ridiculous number of introductory books on Celtic mythology out there. Figuring out which ones are the best can be a daunting task. This already difficult quest is further complicated by the fact that most of these books have extremely generic titles like “Celtic Myths and Legends” or “Celtic Mythology.” At first glance, they all appear to be more or less identical.
But anyone who’s well-acquainted with this field will tell you that nothing could be further from the truth. Some are far superior to others in terms of the scope and accuracy of the information they present, as well as in writing style. Some are written for scholars or an educated audience, while some are written for a more general audience and are written in a more entertaining and engaging way.