Aperture: How It Affects Your Photography & Why You Should Care

The Discerning Photographer posted a good article dealing with aperture from a practical standpoint. This is a subject that tends to be more technical during discussion, so it's nice to see a different approach.

You'll still need to have a basic grasp of f-numbers, but the article is really good about explaining the effects of changing aperture. The two main topics beyond the basics are depth of field and exposure, and the article covers these nicely.