From Google’s viewpoint social signals are an effective way to battle SEO spam, they are an organic signal which can demonstrate whether or not your content is relevant to your target audience. Generating social signals is about creating relevant and engaging content, then placing that content where people can access it and respond to it.
You can generate social signals by making content easy to share with like and share buttons.
Create content with a specific audience in mind, the audience is relative to the channel so think in terms of, video, visual, informative, social, news and events, entertainment.
Google+ is highly influential from a purely SEO perspective. Ensure that your Google+ profile is connected to your website, and spend time building your audience there. Share content, and make sure that a Google+ button is available for people to like and share your content.