I had goose earlier this year - can't quite remember the date - probably not Christmas, though.
Do allow enough time to cook the fat out of the skin. The skin can be flabby and fatty if the bird is not given a long enough cooking time. It is only slightly longer than chicken or turkey, calculated by the weight of the bird
I have a roasting tin with a rack in it and cooked vegetables under the bird, but removed the first lot of fat into a small tin for the potatoes.
I did not cook it beforehand, I have a normal oven, a large microwave and a halogen oven too, so more than enough space for everything to be cooked.