http://money.cnn.com/pf/features/lists/tipping/ How much to tip If you ask 10 people how much to tip in a given situation, you'll get several answers and a slew of hot-headed opinions about the "right" thing to do. To help start your next debate, here's a quick guide to customary gratuities for various services. The guide is provided by the Emily Post Institute. Those with passionate views about how much to tip the pizza- delivery guy, please see the information in the footnote provided by two o