Teachers, guides, textbooks etc are left on this Earth to act as guidelines, signposts and a helping hand to direct us back onto our unique spiritual path when we are lead astray. But in the end we will only receive what we are ready to receive at a specific point of time. There's a Chinese proverb that says "Teachers open the door, but you have to walk in yourself".
Two people might go through the same teaching and come out with completely different feedback. The same person might go through the same experience twice and gather completely different insight on both occasions. I remember clearly reading A New Earth when it first came out and thinking "what a whole load of nonsense", reading it again a few months back shook my perception.
Beyond books, I have found one of the most effective ways to gain insight and induce growth are self study and reflection.
Self study is a skill that moves us away from feeling controlled by our minds to a place where we can detach from the thought process and deal calmly with challenges presented to us. When we study ourselves, our thoughts, emotions, drivers, tendencies we begin to notice destructive habits and reactions enough to see that the world without is a manifestation of the world within. We then recognize that we reflect externally what is already happening internally. Being detached from the thought process we are then able to change our inner world to attract the outer world that we desire.
Reflection provides us with the ability to understand the lessons behind experiences. An automatic thought process, for example, would be annoyed with someone being late for an appointment, someone jumping queues, road works happening somewhere. An awakened thought process will recognize the lessons behind those experiences: have I stole someone else's time? Is there something to be done? Can I lovingly react to this experience? Would another route bring growth to me?
If you need a little nudge or to be inspired, here are some of my all time favorites:
1. A New Earth by Eckhart Tolle
2. The Power of The Subconcious Mind by Joseph Murphy
3. Spontaneous Fullfillment of Desire by Deepak Chopra
4. All books written by Mitch Albom
5. Siddhartha by Heman Hesse
6. A Return to Love by Marianne Williamson
7. Love, Freedom, aloneness by Osho