At the end of 2010, Steve Pavlina released the copyrights on all of his website material. Seeing as Dexterity.com is no longer available, I've added the old Dexterity Software articles to the developer articles section of the site. These made a huge impression on me when I first read them, so I'm happy I can share them here.
These articles are very dense, so it's a good idea to either print them out or bookmark them for when you have some time. Even though the world of software has changed a great deal since these were written, they're still full of valuable information.
I recommend starting with Cultivating Burning Desire and How to Get More Done in Less Time. The articles on marketing and sales are also well worth the time to read, and you're sure to find at least a few actionable ideas to improve your site.