Step 1: Edit photos
Note that I only printed the first two images. The second two are just to help explain how to use multiple layers for alignment. I found it helpful to cut the windows out of the top layer and place them on a separate layer in Photoshop. That way I could hide the layer with the windows temporarily while I dropped my images of mom, dad, Elie, and the squirrel onto a layer under the top layer for scaling. Since the windows are cut out and hidden you will be able to see the people through the openings and scale them to fit. Then you can turn the layer with the windows and doors on and off to test the flaps.
Once you have made the two layers for each page and a front and back cover you can print out all your prints either at home if you have a photo printer or at your local print shop. (I printed mine over the internet to the one hour photo center at Walmart.) I would recommend a matte finish which won't show fingerprints as quickly as glossy.