I am just back from a fantastic holiday weekend at WDW! You are in for some good times!!
Definitely do the AK parade and the holiday parade at the MK. The holiday show in front of the castle at MK was really great also. The special holiday ending to Illuminations was incredible so stay for that too. If you go to AK, back in Camp Minnie Mickey, there are characters in their holiday gear, which makes for cute pictures.
My DH and I also went over to the Grand Floridian today to see their decorations and the Gingerbread house. Both were beautiful. The Boardwalk resort lobby also has a train display that is entirely made of chocolate which is very cool, if you find yourself over there. Downtown Disney also has a nightly tree lighting (6 pm I think) and the decorations there were also lovely.
Happy holidays!