Article marketing is a free way to make money online, you can submit as much articles as you can and these article can send you high targeted traffic which can buy your own product, PLR product or affiliate product. Personally, article writing is my number one money making method all the time.
To write a good article, you should first write main five points, and then you need to write a short paragraph on every point. You should also make sure that your article is written in proper English spelling and grammar. If you want to sell something, try to mention the problem then add a part of the solution and let the reader gets the rest of the solution by visiting your own website or blog. So, you have to add a link to your website at the end of the article.
Where to add your article:
If you haven't an old website, I'd recommend you to submit your article to one of the old and authority websites to be sure that your article will get good search engines rankings traffic. I strongly recommend you to submit your articles to Ezine Articles.com. Ezine Articles is the number one free article directory on the web and gets very high traffic every day. When you write an article targeting a long tail keyword and submit it to Ezine Articles, you will easily find your article at the first place in all search engines for that keyword.
The second good article directory is GoArticles.com, this one allows you to add your direct affiliate link "If you're an affiliate". Ezeine Articles website doesn't allow you to add your direct affiliate link; you can just add a landing page that includes your affiliate link.
Another good article directory is Squidoo.com, it is not really an article directory but they accept all your articles for free. This website is characterized by a good relationship with Google search engine; you can easily get the first place for any long tail keyword when you create a lens there.
I'd also recommend you to submit to HubPages.com, Buzzle.com, and HowToDoThings.com.
Some fast writing tips:
1- Don't submit duplicated content, submit only your own original articles.
2- Don't submit the same article to more than one article directory.
3- Be sure that your article is in proper English spelling and grammar, test it in Word document as it can automatically discover the spelling and grammar errors.