Most aspiring photographers wait until it is too dark to take photos of their lights. If you shoot during the day, you won't see the lights at all. If you wait until it is completely dark, you can have the lights or the surroundings properly exposed, but not both. The key is to find the sweet spot where the ambient (existing) light and the Christmas lights balance.
Get out there early! You don't want to miss the good light. Set your camera up on something sturdy. A tripod is best, but mailboxes work too. Watch the light change and shoot away as the sky starts to darken. Check the screen on the back of the camera and wait for the light to balance. You are looking for the cobalt color sky, with the lights seeming to pop off the image. If you want to kick it up a notch, switch your camera's white balance to tungsten ( the setting that looks like a little lightbulb), it will balance the lights and make the sky go really blue.
Good shooting, and Merry Christmas!
PS If you get some cool images, post them to the Facebook page. I'd love to see your illumination efforts!