It is very simple, copy the following code, and change YOU ADSENSE ADS CODE HERE. to your ads code. done!
 <div class=”storycontent”>
<?php if (($wp_query->current_post == 0)and (!is_home())) : ?>
<div style=”float:right”><br>
YOU ADSENSE ADS CODE HERE.
</div>
<?php endif; $postcnt++; ?>
  <?php the_content(__(‘(more KINGPHP details…)’)); ?>
 </div>