What you'll need.
Some sort of boards to create a solid backing for the decoupage application.
Screws to attach the board
Primer (we used Kilz as it's inexpensive and does a great job)
The paper, whatever you choose to use.
White glue (we bought lapage in the four litre bottle for $15)
Foam brushes (get lots of them, they're cheap and they'll break if you're doing the 200+ sheets like we did)
Trim (metal, wood, whatever you want)
Adhesive (to attach the trim: we used liquid nails)
Step 1: Strengthen and Prep the Surface
We pre-drilled the holes about every 6-8 inches. You can't just screw it in as it'll crush the board. Take the time and pre-drill.
We screwed the boards in and we're relieved to find that they were cut perfectly and fit as they should.
We mounted all the boards and than vacuumed and wiped it down in preparation for the primer.
We primed it with Kilz primer. The only thing we should have done is taped the joins with masking tape first and then painted. Then the wall would have been seamless. The wet paper likes to get into the smallest crack and bubble.