Social media marketing requires proper planning. It does not matter if you are selling chocolate-covered cherries, custom manufactured products, automobiles, financial services or anything else. Your social media marketing will be far more effective if it begins with a well thought out strategy that looks further down the road and focuses on the bigger picture. If you were selling chocolate-covered cherries, you probably could create a Facebook page and sell a few, but you might also consider your audience on a larger scale, where they are spending their time online, and how to reach them through their preferred social channels.
Your social media marketing strategy will be far different from mine, as your product or service, and what differentiates you, is unique. Your SM Strategy needs to be as unique as your offering. The questions I've outlined are not the end-all-be-all to writing your social media strategy, but they are 9 questions (or building blocks) I looked at in detail when mapping out my social media marketing strategy for 2011.
Good luck!