Where should you post your articles…
It depends on your personal goal or goal you have setup for your business. If you want to build an expert name and reputation, then you need to publish our articles in popular newsletters and on topic-relevant highly-trafficked sites makes more sense.
In addition, you can get a good link from such a site to your site which is a good link-building tactic. However, if you are more interested in promoting your own site or blog, a better idea would be to post a full article on your own resource and place a short teaser (with a link to your article) in social networks and communities who share your interests.