This might be of some use to you guys:
<?php
query_posts('cat=1,3,4,19,12,18,11,17,5,14,20,13,15,16,2&showposts=3');
?>
<?php if (have_posts()) : ?>
<?php while (have_posts()) : the_post(); ?>
<div class="postnew"><h2 id="post-<?php the_ID(); ?>">
<a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h2>
<p class="cat">
<?php the_time('M d, Y') ?> by <?php the_author() ?> in <?php the_category(', ') ?></p>
<div class="entry"><?php the_content('Continue reading...'); ?></div>
<p class="postmetadata"><?php edit_post_link('Edit', '', ' | '); ?> <?php comments_popup_link('No Comments »', '1 Comment »', '% Comments »'); ?></p></div><br />
<?php endwhile; ?>
If you only want a specific category to show, find out what the id of that category is by going to Manage --> Categories in your admin panel. Then go to the query_posts section of the code above and put the category(ies) you want after the "cat=" bit. However many posts you want to actually show, just indicate that number by the showposts bit. All the other code, is just there for links, indicating who the author is, dates & times, edit options if you're able to edit, what to indicate if there are 0, 1, or multiple comments, etc. Use this if you have to.
I hope this helps and you will need to place this in the home.php file