It's fairly simple. I use the John Wright Gingerbread house molds. They are cast iron and so easy to use. You don't have to roll out the dough, you simply press it into the molds. A sample of the mold is pictured here.
These molds are available online at Amazon and I've seen some on Ebay. They run about $25 - $35 a piece depending on the design of the house. It may seem pricey, but they will last a lifetime or two. Paula Deen has also come out with a line of Cast Iron Gingerbread house molds, sold at Walmart. They run about $20 - $25 per mold. I haven't used them, but I'm sure they work great.
As for the recipe. I use the recipe that came with my mold. I really like this recipe because it doesn't have any eggs or leavening which keeps the gingerbread house from getting too "puffy" and it cooks up nice and hard. This will make for a sturdy structure that won't fall apart. The only down side; you wouldn't really want to eat this gingerbread. It is edible, but a little too hard on the teeth.
GINGERBREAD (for gingerbread house)
1 1/2 C. shortening
1 1/2 C. granulated sugar
1 1/2 C. dark molasses
12 1/2 T. cold water
9 C. all purpose flour
4 t. ground ginger
4 t. ground cinnamon
1 1/2 t. salt
1. Cream together shortening, sugar, molasses and water.
2. Sift together flour, spices and salt.
3. Add dry ingredients to shortening mixture and mix well.
4. Dough will be stiff. If dough is still crumbly, add a tablespoon of water.
5. Chill at least 1 hour.
6. Press into your mold or roll out and cut into gingerbread house shapes.
7. Bake at 350 degrees for 25 - 45 minutes, depending on the size of your mold or shapes.
8. This Recipe makes 3 large house or 5 small houses. (I made 1 large and 3 small house out of this recipe.)
As for the royal frosting I use.
ROYAL ICING (For Gingerbread House)
6 egg whites at room temperature
1 1/2 t. cream of tarter
2 lb.s confectioners sugar
1. Combine in a mixing bowl and mix on high speed 7-10 minutes.
2. Beat until very stiff - you can't over beat.
3. Store at room temperature, in a covered container.