In this tutorial explains how to add a featured product custom attribute field to the product section using the install script.Please also refer the tutorial which explains how to add custom options to the dropdown.
You can also add the attribute to product page using the magento backend Manage Attribute section.But if you add using the setup script it easy to move files from the development database to live without copy the database changes manually.
This tutorial explains how to read the CSV data from the options.csv exported from the opencart.This file contains the custom options corresponding to the products.Based on the custom options it creates the simple and configurable products.
This tutorial I am explaining how to create new category and assigned the existing products to that categories programmatically based on the attribute.
Using this program I am creating new category named ‘manufacturer‘ under the root category and two subcategories ‘manufacturer1‘ and ‘manufacturer2‘ as shown below and assigning the products to that category.