To me, it's just a time for family. We typically get our families together for a day of food and conversation (or watching football for some). Turkey is the the main course for most American's, with dressing, mashed potatoes or sweet potatoes, beets, and pumpkin pies.
Maybe I should be ashamed, but I really don't know much about the real meaning. The story is that it was a celebration between the original European pilgrims at Plymouth Rock (New England) and native American Indians, to thank God for a great Fall harvest. Some skeptics say the original pilgrims were not at Plymouth Rock, and the Indians were probably forced to celebrate. Who really knows. It's now just a time to gather the family and pig out. ;-)
There is also a Canadian Thanksgiving, but it is on the 2nd Monday of October. It is also a day of thanks to God after the Fall harvest.