The best way for a small business to get started in social media is to do one thing:
Listen to what potential customers & clients are saying about your business.
Listen to what's being said about your competition.
Listen to the questions people are asking as they seek help to find a product or a question they need answered.
Then, you can get started creating the appropriate social media accounts. As you will find out, there's probably not a need to create dozens of accounts. Go to where your customers are talking.