Seo Content writer, need expert

looking for content for website its about 300 pages, with main focus is to educate the user of the content of the page or topic, its all content for marketing services, like Web development, graphic design, hosting services, seo services, also on business development marketing and advertising. second focus is to target the keywords for the pages and make sure content is still for user and its sales the service all pages will have 300-400 words per page, need this done in a timely manner and with two milestones 50% for work, and 50% once work is finalized