The world of WP is huge. So much to find, use and enjoy. And you can easily contribute to this world yourself, for example by designing your own themes or building your own plugins. I won’t talk about themes here though. I’ll do that some other time.
Plugins, however, is interesting … there are so many to choose from, but even so it might be difficult to find exactly what you need. This is when you wish you knew how to build your own plugin. Well, here’s a good place to start: a video tutorial by Mark Jaquith (click the link).
Mark’s tutorial shows you how to build a very simple plugin. Perhaps not very useful, but it will certainly get you started and you can move on from there. However, now that you know how to get started you still have the most difficult part left to do … and that is to decide what your plugin will do! Good luck!