Anyone interested in Celtic Reconstructionism and many followers of Brigit will enjoy and learn from the thoughtful teachings of Erynn Rowan Laurie, Poet, Fili, and Priestess.
Erynn's latest book, Ogam: Weaving Word Wisdom, is an excellent resource. Philip Carr-Gomm, Chosen Chief of the Order of Bards, Ovates & Druids, has this to say about the book: "At last. Magic, poetry and scholarship meet in perfect harmony. I will recommend this book to all students of The Order..."
Though of course her focus in the book is much broader than that of Brigit's Sparkling Flame, among the pieces of information she offers about Brigit is her association with birch, for instance the offering of birch branches to her at Imbolc.
See her website (The Preserving Shrine) for information on her books, ogam readings, etc., links to CR sites and Erynn's LiveJournal. Stop there, also, for access to these articles:
from her website:
The early Irish Brehon law texts ask "What is the preserving shrine? " This question has two answers:
"The preserving shrine is nature and what is preserved in it."
"The preserving shrine is memory and what is preserved in it."
In early Irish practice, poetry and the word were intrinsic components of magic and the worship of deity. The Filidh additionally taught, practiced divination and ritual, did healing work, sought visions, and pursued many other arts for the people and tribes they served.