Our kid started kindergarten reading at about a 4th grade level, and writing like a kindergartner. He was ahead of beginning kindergarten, but not at end of kindergarten.

They moved him into a first grade classroom for language arts, and he has totally caught up to where the highest first graders are. We really didnt do much to help him at home with writing, except give him lots of opportunity to color, draw, paint, use clay, cut, etc.