I'm not fully sure if this will answer your question (I'm relatively new to wordpress hacking), but I use the following code in a custom made template for a page:
<!-- the feed should only use category=3 -->
<p class="..."><a href="feed:<?php bloginfo('url'); ?>/wp-rss2.php?cat=3">RSS FEED</a>
<!-- Only show category=3 here with a max of 5 posts -->
<?php $recent = new WP_Query("cat=3&showposts=5"); while($recent->have_posts()) : $recent->the_post();?>
<li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
Posted by <?php the_author() ?> on <?php the_time('D, jS F, Y') ?>
<?php endwhile; ?>
It does a number of things:
1) Put a title for the block (in [h2])
2) Under the title there is a link to the RSS feed for customers to click on in case they want to subscribe to this feed. The feed includes only posts that belong to a certain category (?cat=3).
3) Within the [ul] block there is a loop that retrieves a maximum of 5 posts that belong to a specific category.
That's it. It might not be the "wordpress way" but it works. If you want ALL posts, just remove the "cat=3" parameter (twice). Likewise, you can retrieve more posts by changing "showposts=5". I had to use trial and error to get the right category number because I couldn't find that in the admin interface. Could be my shortsightedness.
I hope this helps.
Now, I have a related question of my own: when users click on the feed link, the title of the feed (NOT the title of the posts) in the RSS reader is set to the title of my blog. I would like to be able to change this title, more specifically add the category in this case. Any idea how I can do this?