I am skeptical about the "well documented" aspect of this... too much can be said to be documented and still meaningless.
Not to bore anybody to death by quoting this book again, but I have just read a follow up book by Colin Wilson called Beyond The Occult. It's fairly cheap and if you feel like indulging, give it a go. There are a few interesting case studies in there, along with an examination of human consciousness. I found it quite interesting and it helped round out my thoughts.