Japanese American Wedding - Shugi Bukuro?

I am attending a wedding in the United States for a Japanese American good friend and co-worker. I have a Shugi-Bukuro, but have no idea how to put it together and address it. There is an envelope (for money, I assume) and paper folded into a larger envelope. Do I unfold the larger envelop and put the smaller one inside, or just place it in the pocket in the back. How do I address the envelope? There are strips of paper with Japanese characters that I don't understand. The strips of paper have adhesive at one end. The large envelope has decorative wire around it and a decorative wire crane on the front. Also how much money would be appropriate to give?