You need to tweak your theme to allow you to post a message in the mini-cart area (the bit that show “You have no items in your shopping cart”)

This is quite simple.

edit sidebar.phtml

in app/design/frontend/default/modern/template/checkout/cart
add any text you wish to have permanently showing as below
<?php $_items = $this->getRecentItems() ?>
<div>
<?php if(count($_items)): ?>
<h5><?php echo $this->__(‘Recently added item(s)’) ?></h5>
<ol id=”cart-sidebar”>
<?php foreach($_items as $_item): ?>
<?php echo $this->getItemHtml($_item) ?>
<?php endforeach; ?>
</ol>
<script type=”text/javascript”>decorateList(‘cart-sidebar’, ‘non-recursive’)</script>
<?php else: ?>
<div><p><?php echo $this->__(‘You have no items in your shopping cart.’) ?></p></div>
<?php endif ?>
<p>* all orders subject to 3.5% handling fee</p>
<p>* all order are non-refundable</p>
</div>
</div>
<!– [ends] .cart-sidebar // –>