Adding Custom image to eNews box

[Maz]

http://arashmazinani

I have a custom image that I would like to use on the enews box, then have the submit button and section where you enter your email on my image.

I've looked in the style sheet but can't find what I would need to edit on there, I've also had a look in the sidebar.php and also don't know where I can add my image in there.

Does anyone have any idea as to what area of the style sheet/sidebar.php I would need to edit?

my sidebar.php is below

PHP Code:

<div id="sidebar">
        
    <ul id="sidebarwidgeted">
    
    <?php if(get_theme_mod('enews') == 'Yes') { ?>
                
        <li id="enews" class="widget">
            <div class="enews">
                <h4><?php _e("eNews &amp; Updates", 'studiopress'); ?></h4> 
                <form id="subscribe" action="http://feedburner.google.com/fb/a/mailverify" method="post" target="popupwindow" onsubmit="window.open('http://feedburner.google.com/fb/a/mailverify?uri=<?php echo get_theme_mod('enews_id'); ?>', 'popupwindow', 'scrollbars=yes,width=550,height=520');return true">
                    <p>
                        <?php _e("Sign up to receive breaking news", 'studiopress'); ?><br />
                        <?php _e("as well as receive other site updates", 'studiopress'); ?>!
                    </p>
                    <input type="text" value="<?php _e("Enter your email address...", 'studiopress'); ?>" id="subbox" onfocus="if (this.value == '<?php _e("Enter your email address...", 'studiopress'); ?>') {this.value = '';}" onblur="if (this.value == '') {this.value = '<?php _e("Enter your email address...", 'studiopress'); ?>';}" name="email"/>
                    <input type="hidden" value="<?php echo get_theme_mod('enews_id'); ?>" name="uri"/>
                    <input type="hidden" name="loc" value="en_US"/>
                    <input type="submit" value="<?php _e("GO", 'studiopress'); ?>" id="subbutton" />
                </form>    
                   
            </div>
        </li>

    <?php } else { ?>
    <?php } ?> 
        
    <?php if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar('Sidebar Top') ) : ?>
    
        <li id="recent-posts" class="widget">
            <h4><?php _e("Recent Posts", 'studiopress'); ?></h4>
                <ul>
                    <?php wp_get_archives('type=postbypost&limit=5'); ?> 
                </ul>
        </li>
        
    <?php endif; ?>
    
    </ul>
    
    <?php include(TEMPLATEPATH."/sidebar_left.php");?>
    
    <?php include(TEMPLATEPATH."/sidebar_right.php");?>
    
</div>

Thank you in advance.