add keywords to web articles for search engine optimization

We're looking for someone to insert keywords (that we provide) into our online repository of previously written articles on our website to improve search engine optimization. We are very concerned about maintaining the readability and the flow of language of these articles, but would like to key-word them where appropriate. We're a nationally published magazine about video production, so some familiarity with video production would be a big bonus. Start off with a few articles (10) and if we like your work, there's a lot more to go.