Modding can be rather difficult with the sparse Civ4 documentation, and adding BUG's framework into the mix can make it overwhelming. I created BUG's framework to make it easier for modders to add features to BUG and their own mods, and while we have some fairly comprehensive reference documentation, it's mostly useful in helping experienced modders transition their mods to BUG.
What's needed is a good introduction to the BUG framework. To this end I have started a beginner's tutorial called Modding with BUG. It will work through an example mod called Lucky Charms, introducing a new BUG feature on each section with working code demonstrating how to use it. I have also created a tutorial discussion thread on the BUG forum. I will continue adding sections covering more features and eventually move on to intermediate and advanced topics.
Please give us your feedback and suggestions in the discussion thread, and subscribe to it if you want to be notified when I add significant content to the tutorial.