Some sites are setup in a way that is known as "nofollow." Other sites are not, and if you put your article link on them, search engines will be eventually find it in most cases. The more search engines see your link on a variety of sites, the better ranked you will become - there are more complexities.
The simple answer is you put links to your articles on websites. Really, this is a "simple" concept to understand but a complicated thing to master (in my view). Put your articles on Digg, Delicious, and sites like that. Search for "**************** social bookmarking sites." **************** doesn't exist and the term upsets some whiners, but it's just a way of saying that the site is not "nofollow."