"Over the years I have found that following a relatively small number of fundamental guiding principles has helped me become a much more effective programmer."

- http://www.artima.com/weblogs/viewpost.jsp?thread=331531

An interesting shortlist of the things any good programmer should know about. Take a look, it covers those things mentioned in any good programming book or article. After having a look at the list I suggest you read deeper into the topics and improve your programming skills!