Promote web business

I'm looking for a web marketing expert to help promote my web business, which is a tool of loosing weight on line

1. spread the word about my online services across my website

2. Improve page rank and link exhanges

3. Improve and increase our web footprint

I am looking for someone to work on a fixed monthly project basis, and am looking for 5-10 hours a week of work with results. I will be looking for the contractor to generate enough interest.
The website has social media channels ( twitter and Fb) already set up that need to be more active with tweets and posts as well as interactions with other company's social media .
I am happy to work with anyone from anywhere in the world, as long as you have a perfect standard of written English.
Hours: About 20 hours a month
Please send me a plan of actions along with your bid
Thank you
G.