Query to attach a file into database

I new in Drupal and I work so hard to understand this one.. I try to make module (just like WebForm module) and i get trouble to attach a file into database.. I can't insert the value of Information and Attachment in this code.. I know i did something wrong, please tell me..

function nota_form() 
$form['bio'] = array(
    '#type' => 'fieldset',
    '#title' => 'Form Input Data',
    '#description' => 'Please input your data<br><i>*required</i>',
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
  );

$form['bio']['information'] = array(
    '#type' => 'textarea',
    '#title' => 'Information',
	'#default_value' => $information, 
	
  );
 
$form['bio']['attachment'] = array(
    '#type' => 'file',
    '#title' => 'Attachment',
	'#default_value' => $attachment, 
	//'#required' => TRUE
  );

function nota_form_validate($form, &$form_state) {...}

function nota_form_submit($form, &$form_state) {
	
	$informtaion  = $form_state['values']['information'];
	$attachment   = $form_state['values']['attachment'];