Adding Sidebars in WordPress Theme

Use this in your funtions.php to register sidebar

if ( function_exists('register_sidebar') )
    register_sidebar(array('name'=>'Sidebar ',
        'id'=>'sidebar',
        'before_widget' => '<div>',
        'after_widget' => '</div>',
        'before_title' => '<p>',
        'after_title' => '</p>',
));

To use it in your theme use the following

<?php 
    if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar('sidebar') ) :
    endif;
?>

Refer this to know more : http://codex.wordpress.org/Function_Reference/register_sidebar