Meditation in the truest sense is the same regardless of your specifc search.
You are attempting to seek the void by clearing your mind of all outside intrusions and focusing on an aspect that you wish to either attain or accentuate. Learning from any book should be but a few simple lines of technique - anything beyond this is hyperbole designed to make the author rich.
A simple how-to includes,
Finding a quiet spot,
Sitting in contact with the ground (a mat is fine)
Crossing your legs
Sitting up straight
Allow your hands to touch your knees
Close your eyes
Breathe in through your nose and out through the mouth
Clear your thoughts
Focus
It really is that simple - and yet, to attain pure void is a goal that masters have taken years to achieve. The origins are in Eastern religion, so unless you plan on embracing said religion, be wary of mantra or outlines that ask you to say "insert phrase or word here" (Ohm/Am/Om) for example is a religious phrase specific to the Hindu). In Western Philosophy and religion, meditation is simply the reflection on goals to be attained, often to coincide with prayer and or fasting.
Hope this helps. Now go calm down.
ATTENTION - the above mention of religion, philosophy and mantra are strictly used for descriptive manner and are in no way an endorsement, derision or aknowledgement of their core beliefs, faiths or purported effectiveness.