Start by grabbing your camera, lens and tripod, and walking across the road.
Set the camera up on the tripod in your neighbour's front yard (asking for permission might be a good idea) and compose your image.
I would switch to self-timer
mode, and manual exposure, f8 or f11, and just start shooting at a bunch of different shutter speeds, starting from 1/4 second.
Look at the images as you go, and try to assess what's happenning exposure-wise, extending your exposure as you go.
Move back to your side of the street, pull the lens all the way to 18mm and see what your composition looks like now.
Repeat what you've just done; you'll have a different set of shots with a different perspective. Don't be afraid to move around for different viewpoints too.
Remember that your Christmas lights are self-illuminating; that generally means that flash is a no-no. That's why I'd be shooting in manual; in many PHD
modes the camera will be dying to force you to use the flash.
Having said using the flash is a no-no, go right ahead and use it. Switch to rear curtain (not really necessary for static subjects) but cut your shutter speeds back. Be careful of foreground objects that might get burned out, but with careful composition and exposure you should be able to get the house reasonably illuminated, as well as the lights.
Sunset might also help produce some interesting results, especially if you can include some sky in the images.
Two final points: have fun, and post your results.