Gifts for the teacher are usually brought in the day before the holiday break. This is also a good time to bring in gifts to classmates.
If the classroom is going to have a holiday party then gifts should be brought in at that time.
Typically gifts for teachers are given 3 times a year, at Christmas, teacher appreciation week and the end of the school year. Gifts for classmates are given Halloween, Christmas, and Valentines Day.
Before sending in any gifts you should check the rules in your school. Many schools do not allow food items, or have strict rules regarding food items.
Also, you should never feel obligated to give any type of gift.