It was written between 1500BC to about 50BC. It is pretty far out when it comes to the spells and incantations. I didn't get much out of it except it's historical importance in "spiritual" literature. I did however like the book "The Tibetan Book of Living and Dying", put together in about 1991. It is strictly a Buddhist philosophical book. It covers Buddhist philosophy as well as any one book published. I am no longer Buddhist, but when I was it was great reading.
@Bretrick I have it in PDF format, it's with a list of other religious texts, if you pm me with your email address, I will be more than happy to send you a copy.