There are a couple of gluten-free flour mixes out there that you could use in your normal recipes---Bob's Red Mill makes one, and Pamela's has a whole line of baking mixes. So that takes care of baking. For side dishes and stuff, there are so many grains to choose from---rice (I love a wild rice mix for the holidays; Lundberg farms makes a delicious one), quinoa, amaranth, millet, corn polenta, potatoes, etc, etc.

You will manage your usual xmas meal, just watch an stock cube (builiion are ok), spices etc are gluten free. You can buy loads of ready made minemeat pies, christmas puddings etc. Get your butcher to make a batch of gluten free chipploatas. Things have greatly improved over the last 10 years. Just look at the lit of ingredints on anything you would normally buy to make sure. What other things are you thinking of?