This article was published on Smashing Magazine. Below is the quick summary and a link to the full article.
A lot of community extensions (or modules) are available for the feature-rich open-source e-commerce solution Magento but what if they don’t quite work as you want them to? What if you could understand the structure of a Magento module a little better, to the point that you could modify it to suit your needs or, better yet, write your own module from scratch?
Read the full article at Smashing Magazine.