Easiest way is probably to just create a video you want to project. Place it in an FPP connected to a projector. Run the FPP in slave mode and name the video with the same base name as a sequence you are running. If you want to get fancy you can capture some video of your house from the perspective of the projector and then use a video editor to create a mask so that the video only shows on the portions of the house you want. Sean was probably just going to give these same steps but take an hour to do it. 
Gil has it right. When i do the video it will show playing a movie from two FPP's, one projector each. You need to mask the movie, i use power director 14. You need to take a still of your house between where the two projectors will be. Suppose you want "Let It go" and will have a projector on the left side of your house and a second projector on the right. You take the full size video and apply a mask made from teh still picture of teh house. You make a left mask and a right mask. Apply mask to video and make a left video and right video. FPP will keep two projectors synced to within 1 frame. Left projector plays something like frozen_left.mp4 and right projector plays frozen_right.mp4.
adjust projectors so edges touch in the middle. You now have a panaromic projection wrapping around the house.
The tutorial may need to wait, 20 days until my daughter gets married. it is getting busy.
