I'll be speaking at OpenCa.mp this weekend about module development, be sure to come down and check it out as it's sure to be an interesting presentation. I've crammed a lot into 40 minutes, so everyone should walk away with something new. The presentation will be archived and made available here and on the OpenCa.mp site, so check back if you miss the conference.
I spend some time reviewing the basic concepts surrounding module development in Drupal and then dive right in with an overview of a working module. I also spend time discussing some strategies for speeding up development of modules and some of the common pitfalls that you will face.
If you'd like to follow along with the presentation, you can find the source code for the simple module we cover here. It's a simple image carousel based on the jquery cycle plugin. We use a much more advanced version of it in production here at eMUNICATIONS.
Feel free to contact me with questions about the presentation or the code linked below.