Add a custom widget to the WP dashboard with any content you want to include.

Add a widget to the WP Dashboard (functions.php)

// Add custom dashboard widget
add_action('wp_dashboard_setup', 'nabm_dashboard_widget');
function nabm_dashboard_widget() {
global $wp_meta_boxes;
wp_add_dashboard_widget('custom_help_widget', 'ADD WIDGET TITLE HERE', 'custom_dashboard_help');
}
function custom_dashboard_help() {
echo '<p>PLACE YOUR WIDGET CONTENT HERE, INCLUDING HTML.</p>';
}