Is it practical to follow road signs if one rent a car to Great Wall?

You mean you want rent a car and drive on your own to the Great Wall?
If you have a Chinese driving license, it is possible and practical and many Chinese did so.

i would advice to go by taxi , or by train , it's cheap , fast , and trustable .
Of course you can rent a car if you have a Chinese driving license , but if you are not familiar with driving in China , it's dangerous , because the traffic is very busy , and the driving behavior of the Chinese is not the same as in other country's .
I have a license and a car , but traveling in cty's as Beijing , Shanghai, etc , i do by the public transportations , such as train,bus, sub

Thanks Mr. Lucien,

Your reply AND your advice is most appreciated. I am a photographer and I often want to stop to capture some unexpected sight or location. That's difficult to do when using public transportation, but I'm thinking that your advice may be most wise anyway.