To get more static page-like functionality, as well as custom content items that populate a database, check out these modules: Pagesetter
See code in News module for examples. Module Development
Very old guide here. API Reference
See here. Coding standards
http://docs.postnuke.com/index.php?module=Static_Docs&func=view&f=/pncs.htm
Be sure to check out the sections on Storing Values in the database (pnVarPrepFor*() functions) and Securing Forms sections.