How to create backend plugin in wordpress

<?php /*
Plugin Name: book management
Description: This plugin will add/edit/delete Funding Method.
Author: Brainz Technologies
Version: 1.0
*/
$siteurl = get_option('siteurl');
define('BOOKMETHD_FOLDER', dirname(plugin_basename(__FILE__)));
define('BOOKMETHD_URL', $siteurl.'/wp-content/plugins/' . BOOKMETHD_FOLDER);
define('BOOKMETHD_FILE_PATH', dirname(__FILE__));
define('BOOKMETHD_DIR_NAME', basename(BOOKMETHD_FILE_PATH));

// this is the table prefix
global $wpdb;
$bookmethd_table_prefix = $wpdb->prefix;
define('BOOKMETHD_TABLE_PREFIX', $bookmethd_table_prefix);

register_activation_hook(__FILE__,'bookmethd_install');
register_deactivation_hook(__FILE__ ,'bookmethd_uninstall');

//table will be created when plugin is activated.
function bookmethd_install()
{
    global $wpdb;
    $table     = BOOKMETHD_TABLE_PREFIX."book_methods";
    $structure = "CREATE TABLE $table (
                 id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,               
                 book_name VARCHAR(150) NOT NULL,
                 author VARCHAR(150) NOT NULL,
                 department VARCHAR(150) NOT NULL,
                price VARCHAR(150) NOT NULL,
                quantity VARCHAR(150) NOT NULL
                 );";
    $wpdb->query($structure);   
}

//table will be deleted when plugin is deactivated.
function bookmethd_uninstall()
{
    global $wpdb;
    $table     =  BOOKMETHD_TABLE_PREFIX."book_methods";
    $structure =  "DROP TABLE if exists $table";
    $wpdb->query($structure);
}

//show menu on left side
add_action('admin_menu','bookmethd_admin_menu');
function bookmethd_admin_menu(){
  add_menu_page('book Method','Manage book', 10, 'manage_book_method', 'wps_manage_book_method','21');
  add_submenu_page('manage_book_method','Add book ','Add new book',10,'addEdit_book_method','wps_addEdit_book_method');
}

function wps_manage_book_method(){
    include 'manage_book.php';
}


function wps_addEdit_book_method(){   
    $action  = $_GET['action'];
    if($action=='edit'){
        include 'addedit_book_method.php';
    }else{
        include 'add_book.php';       
    }
}

?>
<script type="text/javascript">
function deletebookName(id){ 
  if(confirm("Are you sure to delete?")){ 
   jQuery.ajax({
        url: "../wp-content/plugins/reg_form/delete_book_name.php",
        type: 'post',
        dataType: "html",
        data: { f_ID: id },
        success: function( data ) {
            window.location.href = "../wp-admin/admin.php?page=manage_book_method";
        }
    });
  }
}
</script>
<?php
function getdata( $atts )
{
  global $wpdb;
   $table = $wpdb->prefix."book_methods";
  if(!empty($atts['book_names_id']))  {
  echo "<pre>";
  print_r($atts);
 $book_names = $wpdb->get_results("SELECT * FROM $table where id='".($atts['book_names_id'])."'");
 }
 else
 {
 $book_names = $wpdb->get_results("SELECT * FROM $table");
 }
 $htm="";
 $htm.="<table border='0' cellpadding='2' cellspacing='2' width='70%' style='border:5px solid #cdcdcd;'>
 <tr><td><b>ID.No.</b></td>
 <td><b>Book name</b></td>
 <td><b>Author</b></td>
 <td><b>Department</b></td>
 <td><b>price</b></td>
 <td><b>Quantity</b></td>
  </tr>";
  if($book_names){
      $i=1;
     foreach($book_names as $book){
          $book_names_id=  $book->id;       
          $book_name   = $book->book_name;
           $author  = $book->author;
            $department     = $book->department;
             $price  = $book->price;
           $quantity  = $book->quantity;
  $htm.='<tr><td>'.$book_names_id.'</td>
  <td>'.$book_name.'</td>
  <td>'.$author.'</td>
  <td>'.$department.'</td>
  <td>'.$price.'</td>
  <td>'.$quantity.'</td>
  </tr>';
  }
  $htm.='</table>';
print $htm;
  }
  }
add_shortcode('arjun', 'getdata');


?>