While I am waiting for a client to get his head out of his ass, I have a few minutes to respond to, surprisingly, the most commonly asked question about W&S - meditation. I learned meditation while in the military, continued it through college and until my mid 30s. Then picked it up again during my late 50s, and continue to this day.
I am not an expert on the subject, and I do not understand the physics of the brain. I do not have a clue as to how this shit works. But it does work. That said, I cannot recommend a particular book or a specific method. I know, totally useless.
Spirituality. Whether your path to meditation is through a secular or non-secular means is relevant only to you. For what little it is worth, I believe that the secular approach is more direct and has less confusions. But that is just me.
Some stuff about the process of mediation. Initial attempts will not be easy, and many will get frustrated and quit. It takes discipline and focus. Meditation can be self-taught; difficult, but it can be done. Meditation should not be used to escape, or otherwise avoid reality.
This stuff is personal. You can use directed methods to get started, but you should break away from your meditation tutor as soon as possible. We all have different goals, different needs, different strengths, different weakness, and differing abilities to understand.
You never 'master' meditation. You will reach plateaus of mindfulness and awareness, but there is no such animal is the perfect master of meditation. Anyone that claims to be a 'master' is a scammer or deluded or whacked.
"Logic is the beginning of wisdom, not the end."
- Mr. Spock, The Undiscovered Country