Tutorial in the User Guide

Hi! I'm new to codeigniter and I installed it on my local server and tried following the user Guide Tutorial. Unfortunately, it's kinda vague. he author gives the code sometimes without telling you what file to type the code in. One instance I'm referring to is he presents the code for a function to check if a page exists. Well at this point there are two pages, home and about. He statically uses home as the argument for the view function. He doesn't tell you in what file to put this function nor does he tell you if you must create or modify this function and paste it somewhere else.

I am confused. Can someone tell me what's missing or recommend a more complete tutorial?

Thanks,
Paul