Displaying Category Descriptions in Permanent Theme?

Hi everyone,
I am brand new to WordPress, and am in the process of setting up my page. I’m using the newest version of WordPress and the “Permanent” theme, and would like to display the category descriptions on each page, but I cannot figure out how to do it.

I’ve searched extensively on this forum and elsewhere on the web, and have tried pretty much every suggestion for how to do this. Usually, it is suggested to add some version of this:

<?php echo category_description(); ?>

to the archive.php file. I have been careful in placing it exactly where other posters have said to put it. Those few lines on my archive.php file look like this:

?php $post = $posts[0]; // Hack. Set $post so that the_date() works. ?>
<?php /* If this is a category archive */ if (is_category()) { ?><?php echo category_description( $category_id ); ?>
<h2 class=”pagetitle”>Archive for the ‘<?php single_cat_title(); ?>’ Category</h2> <p><?php echo category_description(); ?></p>

So I THINK I’m doing it right, but am I missing something? I spent about five hours yesterday trying to get this right, but I just can’t figure it out! I’m not a super technical person, so if somebody could explain this in an easy, step-by-step fashion, it would be very much appreciated!!

Thanks!