Good for you! As previously stated, you can expect it to be very busy. I'd recommend familiarizing yourself with the park layouts and having a plan for each. What attractions will you most want to see? Definitely get there for rope drop, focus on getting to the attractions that most interest you and then try to take some time later in the day to take in, observe, and enjoy everything around you. Does
MVMCP interest you? Not sure of the dates around your time and if tickets are still available but they may be special for the kids and give you some extra park time. Request the WDW planning video, print yourself off the park maps, read the Unofficial Guide and I also enjoy Birnbaum's WDW. Have fun planning and make sure you have fun and don't get too overwhelmed because of your limited time and the holiday crowds.