I've added two pages through admin side(About us, online privacy policy)

How do i show the 'About us' link in header section and 'privacy policy' link i the footer portion of client side, dynamically

That actually is dependent on the party's theme you're using. For instance, styles may use wp_list_pages or (in WP3.) wp_nav_menu to instantly list any some pages in your site, the second getting a webpage around the admin aspect where one can determine which pages you would like in every menu defined within the theme.