Reading this should suffice .... no more reading required

Lord Ramana Maharshi answers

D.: Can the mind be fixed to that point? How?
M.: If the mind is distracted, ask the question promptly, “To whom
do these distracting thoughts arise?” That takes you back to the ‘I’
point promptly.

D.: How long can the mind stay or be kept in the Heart?
M.: The period extends by practice.

D.: What happens at the end of the period?
M.: The mind returns to the present normal state. Unity in the Heart
is replaced by variety of phenomena perceived. This is called the
outgoing mind. The heart-going mind is called the resting mind.

D : What is the good of this process?
M:

(a) Conquest of the will - development of concentration.
(b) Conquest of passions - development of dispassion.
(c) Increased practice of virtue - (samatva) equality to all.


Excerpts that mattered me the most from the book "Merging with Siva"

Perhaps the biggest battle in the beginning stages of practicing attention and concentration is the control of breath. The beginner will not want to sit long enough, or not be able to become quiet enough to have a deep, controlled flow of breath. After five minutes, the physical elements of the subconscious mind will become restless. He will want to squirm about. He will sit down to concentrate on the flower and begin thinking of many other things that he should be doing instead: "I should have done my washing first." "I may be staying here for a half an hour. What if I get hungry? Perhaps I should have eaten first." The telephone may ring, and he will wonder who is calling. "Maybe I should get up and answer it," he thinks and then mentally says, "Let it ring. I'm here to concentrate on the flower." If he does not succeed immediately, he will rationalize, "How important can breathing rhythmically be, anyway? I'm breathing all right. This is far too simple to be very important." He will go through all of this within himself, for this is how he has been accustomed to living in the conscious mind, jumping from one thing to the next.

When you sit at attention, view all of the distractions that come as you endeavor to concentrate on one single object, such as a flower. This will show you exactly how the conscious and subconscious mind operate. All of the same distractions come in everyday life. Such concerns have been there life after life, year after year. The habit of becoming constantly distracted makes it impossible for you to truly concentrate the mind or to realize anything other than distractions and the desires of the conscious mind itself.

There comes a time in man's life when he has to put an end to it all. He sits down. He begins to breathe, to ponder and be aware of only one pleasant thing. As he does this, he becomes dynamic and his will becomes strong. His concentration continues on that flow. As his breath becomes more and more regulated, his body becomes quiet and the one great faculty of the soul becomes predominant -- observation, the first faculty of the unfoldment of the soul.