There are around 12 core files. Here is Overview of the main files you will be working with:

• Header.php – Contains everything you’d want to appear at the top of your site.
• Index.php – The core file that load your theme, also act as the homepage.
• Functions.php – A file that can be used to configure the wordpress core,
Without editing core files.
• Sidebar.php – Contains everything you’d want to appear in sidebar.
• Footer.php – Contains everything you’d want to appear at the bottom of your site.
• Archive.php – The template file used when viewing categories, dates, posts by author,etc.
• Single.php – The template file used when viewing the individual post.
• Comments.php – Called at the bottom of single.php file to enable the comments section.
• Page.php – Similar to single.php
• Search.php – The template file used to search display search results.
• 404.php – The template file that display when a 404 error occurs.
• Style.css – All the styling goes here.

Each of these files contains series of php template tag. By using these tags we can insert dynamic content.

• Configuring the stylesheet

All the details of a WordPress theme are contained within the stylesheet. At the top of your style.css add the following code.

/*
Theme Name: Vibidsoft
Theme URI: http://www.vibidsoft.in/
Description: Vibidsoft WordPress theme
Version: 1
Author: Vibidsoft
Author URI: http://www.vibidsoft.in/		
*/

index.php

Open the index.php, add this piece of code and save the file:
<?php get_header(); ?>

<div id="container">

  <?php if(have_posts()) : ?><?php while(have_posts()) : the_post(); ?>

     <div class="post" id="post-<?php the_ID(); ?>">

<h2><a href="<?php the_permalink(); ?>" title="<?php the_title(); ?>">
          <?php the_title(); ?></a></h2>

<div class="entry">

 <?php the_content(); ?>

<p class="postmetadata">
<?php _e('Filed under&#58;'); ?> <?php the_category(', ') ?> <?php _e('by'); ?> 
<?php  the_author(); ?><br />
<?php comments_popup_link('No Comments &#187;', '1 Comment &#187;', '% Comments &#187;'); ?> 
<?php edit_post_link('Edit', ' &#124; ', ''); ?>
</p>

</div>

</div>

<?php endwhile; ?>

<div class="navigation">
<?php posts_nav_link(); ?>
</div>


<?php endif; ?>

</div>

<?php get_sidebar(); ?>

<?php get_footer(); ?>

The index-file now contains the code that calls to the header, sidebar and footer template files

 

header.php

Open the header.php, add this piece of code and save the file:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head profile="http://gmpg.org/xfn/11">

     <title><?php bloginfo('name'); ?><?php wp_title(); ?></title>

     <meta http-equiv="Content-Type" content="<?php bloginfo('html_type'); ?>; 
     charset=<?php bloginfo('charset'); ?>" />	
     <meta name="generator" content="WordPress <?php bloginfo('version'); ?>" /> 
     <!-- leave this for stats please -->

     <link rel="stylesheet" href="<?php bloginfo('stylesheet_url'); ?>" 
     type="text/css" media="screen" />

     <?php wp_get_archives('type=monthly&format=link'); ?>
     <?php //comments_popup_script(); // off by default ?>
     <?php wp_head(); ?>
</head>
<body>

<div id="wrapper">

<div id="header">

<h1><a href="<?php bloginfo('url'); ?>"><?php bloginfo('name'); ?></a></h1>
<?php bloginfo('description'); ?>

</div>

 

footer.php

Open the footer.php, add this piece of code and save the file:
<div id="footer">
<p>
Copyright 2007 <a href="<?php bloginfo('url'); ?>"><?php bloginfo('name'); ?></a>
</p>
</div>

</div></body>
</html>

sidebar.php

Open the sidebar.php, add this piece of code and save the file:
<div class="sidebar">

<ul>

<?php if ( function_exists('dynamic_sidebar') && dynamic_sidebar() ) : else : ?>

	<?php wp_list_pages('depth=3&title_li=<h2>Pages</h2>'); ?>

	<li><h2><?php _e('Categories'); ?></h2>
<ul>
<?php wp_list_cats('sort_column=name&optioncount=1&hierarchical=0'); ?>
</ul>
	</li>

	<li><h2><?php _e('Archives'); ?></h2>
<ul>
<?php wp_get_archives('type=monthly'); ?>
</ul>
</li>

<?php get_links_list(); ?>

<?php endif; ?>

</ul>

</div>