$('.contentwrap img').hide().load(function () {
	$(this).fadeIn(1000);
});

<img src="..." alt="..." onload="$(this).fadeIn();">

.contentwrap img {
    display:none;
}

// fade in images already loaded:
$('.contentwrap img').fadeIn(1000);
// and tell pending images to do the same, once they've finished loading:
$('.contentwrap img').load(function () {
    $(this).fadeIn(1000);
});

$(document).ready(function() {
      // put all your jQuery goodness in here.
  });

$('body').ready(function() {
    //your code here
});