I used to pick out a recipe for every few days. Our goal was 6 different types of cookies. Usually Blonde Brownies, Sandies, Sugar cookies, Chocolate crinkles, Pecan Frosties and some sort of Oatmeal cookie..
Many times the dough does better over night in the fridge, so we would make the batter one day and the next set aside the time to bake them..
Keep in mind, kids get bored with the "work" part of the baking.. So when our daughter was done with her attention, I would wash her hands and let her go and play while I finished. I never expected her to make it through the entire process.
I also used to lay down news paper (taped together) on the kitchen floor to help with the drops and spills.. I made sure to have everything we needed so there was no having to run to the grocery store in the middle of the entire production.