If you are considering starting a winter tea-as-welcome tradition, start with strong flavors, which alway seem more acceptable when it's frigid out, and semi-medicinals to help ward off colds. You might consider having a tea caddy filled wth:
Black Tea with Cinnamon
English or Irish Breakfast
Lemon Herbal or Chamomille
Flavored Green Tea (for the tea-drinker who won't try anything else)
Regular visitors to your home will soon tell you thier favorites -- and may even bring them along for you to have on hand!