You'll find a great overview of how to get started in article marketing here. In addition to the information in that article, you'll also need the following...
- A source of inspiration for new article ideas
- Plenty of practise at writing articles quickly
- More useful information about article marketing
In find my current clients are a wonderful source of new inspiration. Any time a client has a particular problem, or raises a specific challenge, it will inspire an article. For example, the challenges I faced doing SEO work for this contract catering company, and the 'newbie' questions they asked along the way, inspired several articles on this very blog.
Topical forums are another excellent source of article ideas. You'll tend to find both experts and beginners on forums. Beginners ask 'stupid' questions, and experts answer them. This provides great clues about what people want to know in your line of work. If people are asking, they'll certainly read articles about it.
What's more, once you've written an article on a topic, you can refer people to it. Not just once, but over and over and over again across multiple forums. If you get lucky, other people will start linking to it as well. And if you've included a contextual link in that article, it will deliver significant link juice to your site.
This all helps build your virtuous circle, pushing you ever closer to page one of Google.