When the wolves appear just after leaving Hobbiton, run between the rock and the tree directly on your left. This is a patch of brambles that the wolves will not enter. You can safely attack the wolves from this point by positioning yourself close to the rock facing up on the screen. If done correctly, the rock will prevent you from stepping forward while you attack. You may have to run out and back in briefly to lure a wolf over to where you want it, but this is easy enough.