Remember: Scott's buildings come with an inner shell of the destroyed building. They are great looking and extremely robust.
It is a good idea to use a sharpie or similar colored marker to blend/color the cut edge of the paper.
I use Beacon "ZIP DRY(r)" glue, although you may find a good glue for paper or mat board at your local craft store. Check the scrapbook section. Superglue gets brittle and is not the best for paper models.
A PVA glue, such as Elmer's(r) works very well, but you need to use paper clips, binder clips or hot glue as clamps to hold pieces together.
Another handy modeler item is rubber cement. Cheap and effective for holding paper products to a styrofoam or other board and then removing them later. You can lay a battlefield out and pick it all up again, reusing the foam board numerous times - very cost effective.
A couple of notes: Rubber cement works much better than superglue. I also like ZipDry by Beacon. This drys fast but allows repositioning.
Paper clips and binder clips make good clamps. Hot melt glue also makes a decent clamp, but it is unreliable as glue.
I have found the heavy card stock Scott uses is quite durable, I've never had to fortify with styrene.
Use a colored maker, such as a sharpie, to color joints.
Superglue is terrible for paper. Paper flexes, superglue joints do not. Paper also absorbs superglue, making for an area of brittle paper and a weak joint. Check the scrapbooking area of your craft store for good paper to paper glue, and use some before trying to do more elaborate things for chimneys.