For starters, you will have to upload images that are of exact dimensions. The height of the slider defaults to 235px, so unless you have changed it, you will want your image to be the same height. The slider width varies to match your theme, unless you have given it an exact width. The demo slider you saw has an image width of about 400px. Assuming that width will work for you, just upload an image that is 400px wide and 235px high.
Next, you will want to enable the display of the slider title and add some custom text to the slider. All you have to do is drop this code into your theme’s functions.php file:
add_action('promoslider_content', 'promoslider_display_title', 10, 5);
add_action('promoslider_content', 'promoslider_extra_content', 10, 5);
function promoslider_extra_content(){
echo '<div class="promo_slider_extra_content"><< Click image for details...</div>';
}
Finally, you will want to customize the way that the title and custom text appear in the slider. You can drop these lines into your theme’s style.css file:
div.promo_slider_title{background:none; position:absolute; top:15px; right:30px; width:auto; height:auto; padding:0; padding-left:400px; text-align:right; font-size:20px; line-height:20px;}
div.promo_slider_title a{color:#fff;}
div.promo_slider_extra_content{position:absolute; top:100px; right:30px; color:#fff; font-size:12px;}
If you decide to change the width of your images, just change the 400 in padding-left:400px; to the number of pixels wide you want the images to be.