Help me with SEO for my e-commerce website as well as Facebook catalog connection and advertising

I have an e-commerce website up and running with a number of products. I like to have on site and off site search engine optimization as well as fixing any readability issues. In addition I like someone to help me with appropriate keywords, meta descriptions and meta tags. With the aim to improve search engine ranking and organic traffic to my website. Ultimately the aim is to improve conversion and sales.