Seems that all SEO methods out there are focused on company sites or geographically located business. Is there a good method or standard protocol for oscommerce sites with lots of products to sell?
SEO isn't as difficult as most people would have you believe. Simply make your pages keyword optimized for whatever your product is and get traffic and backlinks to it. It may take time but if you send enough people there and your pages are optimized enough you will get ranked in the search engines.
Make sure you install the Header Tags SEO module. It'll allow you to put titles and meta descriptions on your product pages, and every other page on your site, with relative ease.