If you want add “Home” link to your wordpress wp_nav_menu() function then you have to add following code inside your themes function.php file.

add_filter( 'wp_nav_menu_items', 'add_home_link', 10, 2 );
function add_home_link($items, $args) {
if (is_front_page())
$class = 'class="current_page_item"';
else
$class = '';
$homeMenuItem =
'<li ' . $class . '>' .
$args->before .
'<a href="' . home_url( '/' ) . '" title="Home">' .
$args->link_before . 'Home' . $args->link_after .
'</a>' .
$args->after .
'</li>';
$items = $homeMenuItem . $items;
return $items;
}