Donald E. Meek

People get tired of me recommending this book. They'll survive... it's worth recommending. Yes, the author has an axe to grind but he has the historical and philological (is that a word?) stones on which to grind said axe.

If you want to know what all the hype about "Celtic Christianity" is all about - start here. If you have ever wondered how Christianity became "Celtic" when the last time anyone looked it began in the middle east - start here.... :)