Get back where you where with same var.

[eluser]coolfactor[/eluser]
Here's how I would approach this:

1. mock up your various pages.
2. then assign urls to those pages. These urls will determine your controller and function names, and you can begin to map the "flow" from one page to the next.

Example: editing a car - when you click "Save" where will you go next?

You might have /admin/car_edit/<car_id>/ as your url. That tells you that "admin" is your controller, and "car_edit" is your function. <car_id> is the first parameter to that function.

Start simple and build from there. Don't try to understand it all at once.