What are the rules to take before and after you get a perm?

Well i heard your suppose to wash your hair before you perm and then some people say no... so which is it? Also are you suppose to wash your hair with the reconstructor shampoo and conditioner the same night you do it or not? Lastly is it a must to use a special shampoo made for chemically treated hair or you could use any kind? What do you do normally all tips are needed :)