Extra fields on product pages

There is a big need for me to get information from my customers when they are going to buy a product form me. I am looking to add two custom fields on the products page. I know how to add them on the enter shipping page but I am having problem with adding them on the product shopping cart page.

This is what I currently have. If you click on the product you want and you select buy now, it will take you to the shopping cart, Here I have added a custom field. This is where I want the field to be added. The problem is I don’t know how to add this in the mp_shipping_info Can you please tell me how to hook this in so it will process with the mp_shipping_info. As stated I know how to make it process from the shipping information page but since I have put the field in the shopping cart file I dont know how to save and process the information. Here is a screenshot of where I have the fields and I am going to attach the file I am editing