A somewhat upsetting statement that I can make to the reader is that a huge amount of information on mysticism, the occult, meditation, and what have you consists of theoretical models being copied and passed on without any real experience that goes behind the writing.
The upside of this, of course, is that we have the maps, the theories, the knowledge. The downside is that it includes a lot of distortion and omissions.
For instance, we'll hear a great deal about the power of the Third Eye in meditation and also in energy work, but I've rarely come across anyone mentioning that the Heart Chakra is also an immense center of mystical power and a center by which mystical power can be enacted. I find it quite strange that something so obvious through meditation and energy work would get left out of the books so consistently, yet here we are.
Explore on your own. Experiment and document on your own. Find out for yourself, even if the books are guiding you.