How to add 4 posts to home page of website?

If you are not an experienced PHP programmer, this could be a bit much to tackle. Here is a general outline of what needs to be done.

Each of the 4 posts will need a block of code similar to this:

<?php $temp_query = clone $wp_query;
<div class='leftbox'>
   $more = 0;
   query_posts('category_name=jobseeker&posts_per_page=1');
   if (!have_posts())
      echo "Sorry, no Job Seeker message today."; ?>
   <?php while (have_posts()) : the_post(); ?>
      <div class="post" id="post-<?php the_ID(); ?>">
         <h4><?php the_title(); ?></h4>
	<div class="entry">
            <?php the_content(); ?>
         </div>
      </div>
   <?php endwhile;
   ?>
</div>

The $temp_query = clone $wp_query; will be done only before the first block. After the last block, use $wp_query = clone $temp_query; to restore $wp_query.

The div class=’leftbox’ will alternate with div class=’rightbox’ to put the posts side-by-side. The classes must be defined in your CSS file for the correct alignment.

Replace the category_name in each block with the desired one for that block. Alter the ‘No message’ statement as needed.

Hope that gives you enough to go on.