A Danish (I think Danish anyway) has put together a great step by step tutorial about how he setup the background and lighting for a Christmas card family portrait. Called The Making of a Christmas Card it details building a light panel, positioning two flash units, and incorporating a gobo. It's tutorials like this that make lighting so much easier to understand for photographers looking to take the next step up from using only available light and on on-camera flash. It's definitely worth looking at if you're interested in portrait lighting.