I use Lineco pH-neutral PVA glue that I get at an art supply store. Other companies make PVA glue, though. Basically, it is a purer form of Elmer's. It is a little bit thinner, but not messily so. For application in small areas, I use a toothpick. Just by a big box and keep it on your work table. When the tips get gunked up, just put the toothpick aside and get a new one. After the glue has dried on the first toothpick, just cut a new tip. For larger areas, I use a run-of-the-mill Testor's paint brush. When it comes to weighting things down or clamping while the glue dries, every seam requires a different approach, it seems. (A pun there....) For a straight butt joint, what I generally do is glue the joint, cover each side with a bit of wax paper, then lay small strips of wood on the wax paper and clamp it with clothespins. For joints were I want to apply weight, I generally weigh it down with prescription pill bottles filled with pennies. I always seemed to have a bunch of pennies and pill bottles laying around, so it seemed a good use. The cap of the pill bottle is flat, so they stay in place. Plus, you can vary their weight by varying the number of pennies you put in them. When I do weigh things down, though, I usually don't put the weight directly on the paper. I generally cover the paper with a small piece of wood strip, then put the weight on it. The wood strip distributes the weight.