The content you create should be shared on the social networks on which you're active. (And if you're not active on any, this is one of the reasons to get started.) Moreover, Google's algorithm considers social signals as one of its most important ranking factors -- socially shared content is a vote of approval, or at the very least importance, so it makes sense Google would consider it when deciding whether a post should rank well in organic search.
Practice article writing. Learn how to write a newspaper article and how to write a wikiHow article. As a professional content writer, you may find a position that focuses on journalistic article style writing, or more educational how to writing. Study the form, structure, voice, and tone of each type of article so you are familiar with both types.
For example, a car insurance company could use a headline like this: “Are You Paying Too Much for Your Car Insurance?” The ad would then go on to talk about how most customers pay more than they need for car insurance, and how company X can save them more money (which is something similar to what GEICO currently does). The purpose of the ad is first to focus on the pain, and then to talk about how Company X alleviates that pain.
When the marketing team starts to grow, who leads content marketing gets more interesting. With a team of three marketers, you can approach content marketing a couple ways. Either one person can own content marketing activities, while the other two own activities that align more with the middle- and bottom-of the funnel. Or, two people can own content marketing activities, while the third owns the rest.
Those scenarios might have sounded like a lot of work to you, especially when considered alongside marketing programs that provide more immediate gratification -- like list purchasing, PPC, or trade show marketing that deliver names and email addresses in mere minutes. Often, content marketing is used when businesses realize those programs are either ineffective, too expensive, not scalable, or all of the above. Here's what I mean, using the "infographic generator" example above for demonstrations.