Choose a position that is comfortable, most people like to sit down, with their legs crossed, with their back straight up and down. You can also sit on a straight backed chair with feet flat on the floor with your arms comfortably on your lap. Some choose to lie down but if you get too comfortable you will end up asleep. :D
Next you should close your eyes and try, in whatever way works best, to clear your mind.
Some people focus on the dark space behind their eyelids, and just focusing on it until all other thoughts in the mind subside. Others like myself, go through and relax all areas of the body then focus on breathing in and out. When a random thought enters acknowledge it then let it go, then return to the breathing.
Once you get to the state where all your thoughts have cleared, and your mind is quiet (ex; you aren?t thinking of random things anymore) you can do many things:
Taken from this article, which you should read. It concerns the basics: