How to sleep well

This week I read this article from here.

According to new study, sleeping six hours or fewer or ten hours or more a night lead to health problem such as diabetes, heart disease and obesity. Sleeping longer is not linked that to have a good sleep, when and how we sleep is important. When I read this article, I was surprised because I had thought that sleeping longer is linked with a good sleep. I feel good after I sleep longer. Recently,feeling stressed in our life becoming a serious health problem. In addition, it is said that heelth problem is linked with stress, but if we knew how to sleep well and feel good in our sleeping time, I think that it leads to solve general health problem easily. I usually sleep about six or seven hours, and I thought I need to keep this length and sleep comfortably because I having a good sleeping is a easy way to keep our health better. I have two question for disscution, 1, How long do you usually sleep if you feel good? 2, Do you think that we need a health education at school?