I would like to know what human being with a normal life can possibly wait EXACTLY two hours for dough to chill. Of course it can be more, and it could be less, too. Also, not all refrigerators have the same tempreature, and dough will cool faster if the container is wide and flat or narrow and tall, so two hours is necessarily an approximation. I get so mad with recipes that give these arbitrary directions, as if people have nothing to do but wait around twiddling their thumbs for two hours!
If you're going to want to do it the next day, you want to make sure it's easy to roll out when it's good and hard, so flatten the dough, even into a few disks if you have a lot of dough, maybe an inch or so high, (approximately!) and wrap in plastic before refrigerating. And if, instead of wanting to wait, next time you're in a hurry and want to bake right away, you flatten it and put it in the freezer for something like ten minutes and you probably will find you can roll it out already. The idea is simply that you will need less flour if the dough is cold, because the cold keeps it from being sticky, and the less flour you use, the better and butterier the cookies are.
You need to flatten them in either case, so you won;t have the phenomenon of taking them out and the outside getting soft and the inside still being hard.
Take them out when you're ready to roll. Put the first on the board and hammer it with the rolling pin, all over. Just whack it all over with the flat of the rolling pin. That will soften it enough to be able to roll it. If it doesn't roll and still cracks, whack some more, or go make yourself a tea and come back to it. The others will meanwhile be getting slightly warmer, but being thin, won;t get warm and soft and sticky on the outside while being hard inside.  | 
Overnight chilling... 
