function insert_post_type_on_activation() {


  $Post = wp_insert_post(
			array(
				'post_title'     => __('test post', 'wepguest'),
				'post_content'   => 'test content',
				'post_status'    => 'publish',
				'post_author'    => 1,
				'post_type'      => 'book',
				'comment_status' => 'closed'
			)
		);

}




register_activation_hook(your_PLUGIN_FILE, 'insert_post_type_on_activation');