very simple to train a cat to use a litter box. Just set him down in it and rub his front and back paws in the litter. You might have to do this a couple times, but all three of my cats picked it up first go.
Re the clawing, if you get little scratching posts and sprinkle them with catnip they'd much prefer scratching that than your furniture.
Cats are the easiest animals in the world to take care of.
http://www.google.com/search?sourcei...ratching+posts