Google Shopping Inputting of Mandatory Attributes for Magento Website

We have a Magento site with over 900 products. We have a feed from the site to google shopping. The feed appears to be working fine but there are missing mandatory attributes required by google shopping. We need someone to look at this and fix the critical issues i.e. input the attributes so our products appear in google shopping. I realise that this is a bit of an admin job but it needs someone with some experience of Magento / Google Shopping as well. We require this to be done quickly. Many thanks.