Where do I stick it? (be nice now)

[eluser]John Pantoja[/eluser]
I should throw you more information. If you're not familiar with MVC, I do believe CI wiki has a good prep. In a nutshell: (and if I understand CI correctly .. not the MVC part)

Model - your database interaction code, CRUD
View - your html and code to display your dynamic or static data
Controller - your application logic to interact between your model and view and other code.

Library - Your code that extends CI or application specific code (OOP)
Helper - highly specific functions, collection of functions, good old fashion procedural code.
Plugins - basically just one function and procedural as well