next/previous

Maybe a simple question but here goes: this is code I am using to display posts on a page. I need to navigate to more posts, forward and back. I want navigation above and below the posts (top and bottom of page. I there are lots of possibilities, I think but which will work for my case? Anyone?

<table>
  <tr>
    <td>

<?php $myquery = new WP_Query(); $myquery->query('posts_per_page=6&cat=6,4'); ?>
<?php while ($myquery->have_posts()) : $myquery->the_post(); ?>
    <div id="news">
    <div class="single" id="post-<?php the_ID(); ?>">
      <a href="<?php the_permalink(); ?>">
      <?php if(has_post_thumbnail()) {  ?>
      <?php the_post_thumbnail('large');?>
      <?php } else { ?>
      <img src="<?php bloginfo('template_url'); ?>/images/no_image.png" alt="no image available"/>
      <?php } ?></a>
      <h3><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h3>
      </div><!--single-->
      </div><!--news-->
    <?php endwhile; ?>
    </td>
  </tr>
</table>