By "climbing simulators" do you mean setting replicas of specific climbs/cruxes? Or do you just mean setting?
For climbing simulators, I don't think there's much literature out there, since so few people do it. As for setting in general, here are the two best resources I've come across (in my limited research):
The Art of Course Setting was the book I was thinking of. Thanks Ty, but I think the link is broken. No specific climbs in mind but when trying to set a certain grade it helps think of real climbs at that grade. Thanks for the help Earthlings.