This looks like a rather definitive guide: http://www.seriouseats.com/2009/10/the-food-lab-science-of-how-to-cook-perfect-boiled-eggs.html
This looks like a rather definitive guide: http://www.seriouseats.com/2009/10/the-food-lab-science-of-how-to-cook-perfect-boiled-eggs.html