Social Media Manager

This is for a new website targeting work at home Mums. I am looking for an experienced social media person, who can set up, update and communicate through 4 social media sites: Facebook,Twitter,G+ and Pinterest. I am also looking for a simple, clear strategy to target each media differently so there is a purpose for a person to follow on different media.

The site (in development) already has lots of content which can be re-used. I am looking to target a specific market and would prefer genuine interaction with 100's rather than 1000 of random people.