Look in the /ndxz-studio/site/plugin folder...you have two kinds of plugins:
- exhibit (for the presentation of images)
- plugin (for things coming out of the textarea when you edit a page
The 'about this site' plugin is a little hard to track down...it's found in the /plugin/index.php file but it's hard wired into the system - so it's not the best example.
If you'are handy with PHP you'll see how easy it is...just check out how the naming convention should be right (like plug:wordpress some='vars' /) and how you connect to the database. The rest is just looping things out.
Let me know how it goes...maybe I'll have a little time next week to give you a hand assuming you aren't trying anything too complicated. ;)