Dear Khun Sunthorn
May I suggest you to read the second part of my writing on this subject as well as my previous writing on the cultivation of Sati and well-being (การเจริญสติกับสุขภาวะ) on this web blog. If you like, you may follow its third part that I will write it very soon. However, I would like to remind you that it is impossible to truely understand the minfulness or vipassana meditation without practicing by yourself. Seriously, I would strongly recommend you to find free time and a right teacher for practicing it.
Best wishes,
Pa-thai Yenchitsomanus.