Some of you may be wondering what's the difference in writing articles and posting them for free to article sites that offer free content and the content mills derided by professional writers. Recently Angela Hoy fielded questions about this on Writers Weekly. Visit her there if you'd like some background on this subject or want to read her comments.
There are a lot of websites where you can post articles with the expectation that your bio and links will be posted along with the free articles. Sites like ArticleCity, EzineArticles, GoArticles or any of the other websites can help drive traffic to your website.
I won't name any names here because some good people work for them under the impression that they're building a professional writing portfolio. I see no reason to bring those struggling writers any more distress related to their work for the mills than they already receive.
Basically, the content mills say they will pay you for articles. The pay is very low and very slow in coming, and the hoops they make you jump through are often insulting.
Legitimate article sites can help you so make sure you choose wisely.