Social is a big field so let's start by understanding a little more about your goals first...
What sort of industry are you looking to promote a business in?
Do you have an established customer base? Are they creating any content on your behalf [reviews, testimonials, videos, photos, etc].
Do you have any staff that can create relevant content or drive expert opinion in the field?
What is your business goal for a social media program? Are you ok with engaging rather than immediately selling? Do you understand why I'd ask?