First and foremost thing, Stick to your routine. Use social media daily. Don't market or promote products each time you use social media sites. First you need to gain trust, help followers by answering their questions, engage with them on regular basis. Last but not least share informative content so that people like and share your content.
SMO is the best for launching and promote your website. Use fresh and quality content for your website page's. Create your business page than add new status and attractive pictures regarding your business. And there are so many activities for SMO. So read tutorials about SMO.