When I first started meditating I couldn't quiet my mind, so I used guided meditations from Youtube and that helped a lot. Also, the simple mantra "Om" (pronounced aum) is very helpful when you can't quiet your mind. When you say it properly the vibration you feel in your forehead from saying it, helps to "awaken" your pineal gland (your third eye).
Also, focusing on your chakras and envisioning their colors and them opening is a great way to keep your mind quiet.
I have found that since I started eating almost all fruits for my nutrition, my meditations are amazing. I can't imagine not meditating at this point in my life.