If you can roast a chicken (see my post “Roasted Chicken”), you can roast a duck; it requires only a few extra steps. It’s best to truss your duck, as shown: After removing any excess skin or fat, tuck the wings under, anchor some twine under the back and above the wings, and then wrap around the legs and tie to hold them together.
To render some of the fat from the skin, immerse the duck in a pot of cold water and bring to a boil. Reduce heat and simmer for about 5 minutes (the skin should start to tighten). Remove from water and score the breast skin with a sharp knife.
Oil and season the duck and place in a roasting pan over some fruit and vegetables, such as apples and brussels sprouts. Roast at 350 degrees for 40-45 minutes. If the fruit and vegetables are ready, remove them. The breast should still be pink, and the skin golden.
To brown and crisp up the skin, place under the broiler. At this point, you can remove either the breasts or the legs from the carcass. If you remove the breasts, set them aside to rest and continue to roast the carcass with the legs until the juices of the thigh run clear. If you remove the legs, set aside the carcass with the breasts to rest and continue roasting the legs until done. My boyfriend prefers the latter method, because you do not cut into the breast meat until after it has rested on the carcass. This retains more of the juices.
Here is an article that describes a somewhat alternate technique: