Scan them with any scanning device that you have, then use a graphics program with "layers", which is where you can put multiple images on top of each other so that you can see through them, kind of like the wax paper that construction designers might use to lay out a floor plan. Photoshop is great, but a couple free alternatives are Gimp or Paint.net.
Open the program and familiarize yourself with it if you've never used it before. Take the scanned pictures and crop them so that the images you want are side by side on each page. It would be a good idea to look up how to set the dimensions of your image to match the dimensions of a real piece of paper so that it prints properly. Here's an example of what "cropping images" might look like:
Now what you would do is create a new layer and consider it the back of your page. Your layer should be transparent so you see the image above and it looks like nothing happened.
With your current layer active, start cropping the images for your second page. Since you can see the first page underneath, you can easily align the corners in a visually accurate way, as shown below in this example (you normally won't see through the image unless it's transparent):
This is an arduous process that will take time. If your overall goal is to print out a professional scrapbook, then you could order one online using one of the many existing scrapbook makers out there