Just sent
blackwingbear a message on this and figured that some of the other humans I know might be interested too. Anyone into things Celtic should check out Peter Berresford Ellis' The Druids. I picked the book up used on a lark and was astonished to find an excellent piece of historical theory.
If you're world view is locked in granite over the idea that druids were anything like the character class in D&D then don't read this book. Ellis shoots down the most widely and dearly heald misconceptions about the druids and backs his theories up with rigorous research and damned good evidence.
This was the quote that sold me on the book: "Readable and well-researched . . . A useful guide to those who wish to learn more." - Count Nikolai Tolstoy
Tolstoy!
It wasn't until after I'd bought the book that I realized it couldn't be the Tolstoy I'd thought of since "The Druids" was first published in 1994. But still, it's an excellent book.