I'd like to recommend a book I've read recently. It's called "Journey of Souls", written by Dr. Michael Newton.
It's about the mentioned Dr. Michael Newton, a hypnotherapist, who was regressing his clients in their previous lives. Beside that, he also developed a technique to regress them in a 'world' between lives - so called - spirit world/realm.
Main topics in the book are:
- how it feels to die - how you choose another body to return to Earth
- what you see and feel right after death - different levels of souls: beginning, intermediate and advanced
- spiritual guides - when and where you first learn to recognize soulmates on Earth
- what happens to "disturbed" souls - the purpose of life and manifestations of a "creator"
- why you are assigned to certain soul groups in the spirit world
and what you do there
Regardless this specific content which can be a controversial topic, it's an interesting reading material.