If you want to customize your sorting on category page's toolbar section, please follow below given suggested method: Create a custom module for overriding Catalog/Block/Product/List/Toolbar.php For that , you must follow the procudure to create a custom module in magento as:

    
        
            true
            local
        
    

Above code should be placed in your app/etc/modules and name the xml file with Eglobe_Catalog.xml Next step is, remember to add your local/Eglobe/Catalog/etc/config.xml with below given code:
 

    
         1.1.3
    



  
     Eglobe_Catalog_Block
             
  
      
        Eglobe_Catalog_Block_Product_List_Toolbar
      
  



Finally override the Mage_Catalog_Block_Product_List_Toolbar.php file by the following code.
class Eglobe_Catalog_Block_Product_List_Toolbar extends Mage_Catalog_Block_Product_List_Toolbar
{
    /**
     * List of available custom sort types
     *
     * @var array
     */
    public function getAvailableOrders()
    {
        return array(
            'created_at' => $this->__('Date'), //set the sort type by new product came in for category
            'name' => $this->__('Name'),
            'price' => $this->__('Price')
        );
    }    
}