Here is a Sample of Some Jquery Code that you can use to make the effect you want.
$(window).scroll(function () {
if ($(this).scrollTop() > 125) {
$('#DivYouWantToAnimate').css('visibility', "visible").animate({ paddingLeft: "150px", opacity: '1' }, 'slow');
}
});
Remember to set the default of the Div you want to animate to Visibility: Hidden; so it will show itself only when you scroll down.
Here is a fiddle with the Animation ( ScrollDOWN to see the effect )
EDIT: Remember you can change the effects of the jQuery so it looks more smooth than my example.