Holiday tipping is emphasized more in some areas than others: in the suburbs of Middle America, it can be relatively uncommon, while in some buildings in New York, it's required. Not tipping your doorman can be like slamming the door in his face.
The custom of holiday tipping may have begun because people in certain professions provide services that are worth far more than they're actually paid to perform them, and because people who work hard for lousy wages might need a little holiday financial help from grateful patrons. Either way, neglecting to tip the right people at this time of year can be a social disaster... but who are those people, and what should you give them?
Blueprint magazine has an article on their site (also published in their November/December issue, currently on news-stands): the Holiday Tip Sheet. It has etiquette advice and a printable chart (PDF) to help you figure out who (and how much) you should tip during the upcoming season, and who should receive a gift, either because they can't accept cash, can't accept gifts over a certain monetary value, or really deserve something more personal than money. Ideas for what to do when you're on a tight budget are also included.
With Blueprint's help, you'll have no problem showing the people who help you out how much you appreciate them.