Well you can hire a SEO expert who can provide this type of things: Review of your site content or structure Technical advice on website development: for example, hosting, redirects, error pages, use of JavaScript Content development Management of online business development campaigns Keyword research SEO training Expertise in specific markets and geographies. http://www.google.com/support/webmasters/bin/answer.py?answer=35291 Red more there.
at first its important to complete the on page SEO. then Go for Off page. add your title tag, meta description, meta keywords. watch the strategies of the competitors sites. then try to do the same things that they have done. it will definitely help you. thanks