Peter Della Santina
Meditation: The Heart of Buddhism
The Basic Method of Meditation
The Four Foundations of Mindfulness Meditation
Mindfulness With Breathing: Getting Started
Essential Advice on Meditation
Bibliography, Links, Resources
What is missing in focusing total attention to one single object all the time is wisdom. Your total attention should be coupled with wise attention.
See Ashoka's online course Zen Meditation: Entering the Path, for an in-depth introduction to the Zen meditation.
See Ashoka's online course Turning the Mind Into an Ally for an in-depth introduction to taming the mind withShamatha meditation.