That book that you may or may not now have can be brilliant for using as "templates" for making foamcore buildings, print them out then transfer to the foamcore, instant template!! Do you trace them and then cut out only certain parts in foamcore? Not sure how to do the corners & tabs because of the added thickness.
1.Print them out(the hard part is figuring which page belongs to what
2.Cut out the pieces, including doors and windows
3.Use sticky tape to join the sides, front, back, etc together to form your template.
4.Trace/glue/sticky tape this onto thick card...
5.Cut it out
It its now at this point that you have a choice of which way to build it. I simply transfer it onto my foamcore and cut it out, when it comes to the wall joints i just cut half way through the foamcore and bend it into the box it needs to be(the paper at the back you didnt cut through holds it all together). The gaps at the corners are filled with balsa wood, cut to size(either flush or sticking out a little for character)
You could also just cut out all the walls and join them,(note that the roof as printed may not fit depending on which method you use!!)
Once the glue dries, its a simple matter to cut a roof out of thick card, then add details..... more card in various strips to add to the walls. I also use match sticks etc etc for windows(and window sills), doorways etc etc. Use your imagination, the more details you put the better the model.
Then for the roof.......
Cut twice as many tiles as you think you'll need for the roof. Then make three times that. It should be enough for half the roof. Glue.