Thanks for the replies - Jeffrey - I am looking for historical data (folklore and oral traditions can also be a valid source of historical data/insight in my opinion)
Dathi - that looks very interesting , - thanks
Actually I have a theory about how Druidry is practised now. Its obviously got very little in common , historically , with the ancient druids - but I don't think that matters .
My theory is based on ecology. When the dinosaurs were around there were different ecological niches that still exist now. One for example is "large predator" before this niche was occupied by a T-rex now it is occupied by a lion. The best example is coral reef. There was coral reef millions of years ago before one of the great exctinction events - this completely killed off these corals who were actually completely unrelated to any of the organisms found in a modern coral reef.
Thats what I think about modern druidry - its fulfilling a cultural and spiritual niche that has been left empty by industrialisation and religions that take you away from nature .