Jonathan Nackstrand/AFP/Getty Images

Prince William and Kate Middleton are following the edict that "it is better to give than to receive" when it comes to planning their first holiday season together.

The Duke and Duchess of Cambridge will kick-off their Christmas week celebrations on Dec. 19, with William's brother, Prince Harry, in tow, by attending the "A Night of Heroes: The Sun Military Awards," or the "Millies," to honor servicemen and servicewomen in the U.K.

Two days later, on Dec. 21, the royal couple, married since April, will visit London-based charity Centrepoint, People magazine reported.

According to the magazine, William was introduced to the charity, which works to help young homeless people, by his late mother, Princess Diana, and now serves as its patron.

The Duke and Duchess will reportedly join Centrepoint youth in a healthy cooking lesson, attend a performance from the winner of a "Centrepoint's Got Talent " show and watch a group session of the charity's "Workwise" program.

In their off-duty hours, William and Kate, both 29, will be surrounded by family.

They'll spend Christmas weekend and Christmas Day with the entire royal family at Sandringham Manor, the Norfolk, England, retreat of William's grandmother, Queen Elizabeth.

Helping Middleton feel more at home with her new, royal family will be her younger sister, Pippa.

People reported that the Queen has invited Pippa, 27, to join the family for their traditional Boxing Day pheasant shoot on Dec. 26, an event normally reserved for royals only.

Up next for the couple will be a chance for Kate to introduce her new husband to the traditions of her own family.

A source told US magazine that Kate, William and Pippa, "will all travel together back to Bucklebury and spend the remaining days of Christmas with the other Middleton family members," following their attendance at the Boxing Day shoot.

Adding to the holiday buzz surrounding the couple is growing speculation that this could be William and Kate's first, and last, Christmas together as just a family of two.

Rumors that Kate is pregnant with the couple's first child, a potential heir to the throne, have swirled after she first refused to eat a product containing peanuts, off limits for expectant moms, at a charity event in Denmark, and then appeared to conspicuously hide her belly with her purse while attending a charity concert earlier this month with William, Prince Charles and his wife, Camilla Parker Bowles.