The best article format to use is one that will bring traffic to your website... In all seriousness
however, a standard format for an article is structured as the following:

Introduction - Introduce the reader to what you are going to talk about. In this
section you don't talk about facts and figures, or support your position. You are
merely stating your position an the subject.

Body - This section is where you make your case, and produce the facts and figures.
This is the section that explains the top 3 reasons why..... or the little known 4 secrets of.....
or just explain why Macs are better than PC's, or why Ruby on Rails is better than PHP.

Conclusion - this is where you restate your point and remind them why you took the position
that you took. IN this section, you typically don't introduce new facts, however when it comes
to the Internet and getting traffic to your website, I find that leaving them wanting more
by mentioning a new point, will make them more likely to go to your web site.

You can find more info on how to write articles that drive traffic to your website with this
article marketing resource.