Being raised a JW, I had all the brainwashing regarding the demons taking over an empty mind. Therefore, when I started using a meditation CD called "The Daily Dose," it was really HARD to get my mind quiet and following the guided mediation. But I benefitted tremedously from even the little bit of focus I received from doing it.
I have seen some crazy demon things through the years, but now that I think about it, nothing in like the last 20 years. And I think they came to visit me a night they attacked a sister I knew. She took interest in spiritistic things, I didn't and won't have anything to do with them.
There are several programs as mentioned that are introductory to meditation...I would recommend anyone investigating it and doing it to their comfort level, which will get broader as you go along. It calms the heart, mind...it helps you focus and gives you clarity. It is a wonderful thing.
I am reading a fascinating book called "The Power of the Subconsious Mind" by Joseph Murphy. It helps you understand how powerful thoughts are and how important it is to seed the mid with positive thoughts/words. The results are amazing. Thoughts are energy, and you can change life by changing the way you think. I am so loving this knowledge.
Good luck!