There's a great book by an american scientist that regressed some woman without realising into loads of her previous lives, he also got to speak to these "masters" in her transition periods, or guides that are supposed to help you judge what you've done....

Think its called "Many Lives, Many Masters"... yeah checked on amazon:

http://www.amazon.co.uk/exec/obidos/...303203-1642233

Very interesting, written by a complete non-believer.

My own beliefs are a bit different tho