I would like to start my own social marketing business. Any suggestions?

[Jake]

It all depends on your skills or resources, you could start by doing small chores to order at microtask sites like mturk.com, or microworkers.com, or offer a specific service for $5 at Fiverr.com (you earn slightly under $4) these could be good for someone who needs some experience.
If you have good promotion and management you might be able to offer a number of services on your own business site, while recruiting active social media users as your outsourced workers wither through marketplaces like Elance, Odesk or on your own separate social worker "employment" site, there can be a lot of labor involve in social media, having a stable of oursourced help would help you scale things up.