I've had some experiences with lucid dreaming about 15-20 years ago. Stephen LaBerge is a well known author (and leading scientist) in this dimension. His book "exploring the world of lucid dreaming" gives a good introduction. It gives you techniques (more or less easy to learn) how to get awake while asleep. Lucid dreaming can be used just for fun, for therapeutic reasons, or what you are looking for, for spiritual development.
But to do that, you first have to learn, how to get awake whilst asleep, then to keep your conscious stable while dreaming. Once there is enough stability you can "literaly" decide what you wanna do (fun, meditation, dealing with psychological stuff, etc.). So I guess this book would be a good start to learn the techniques, so that you later can dive into dream yoga a bit deeper.
