he problem is this from style.css
#main {
width: 9000px;
height: 1200px;
margin: 0 auto;
background-image:url('http://littleboxcreative.com/img/plum.png');
}
You will need to have it within a container set to overflow:hidden ie
#maincontainer {
width:980px;
overflow:hidden
}
This hides everything except the first 980px, then your slider slides in the next when the user scrolls.
Once you have fixed that then you will need to add some jQuery to allow the user to move between your #mainwrap panels, or set it to autoplay as a slider.