Nodes

I've been developing for some years using ms active server pages but more recently osCommerce. The problem I find with osCommerce is that you have to change the core product to get what you want so I been looking at and experimenting with Drupal. The idea of not touching the core product appeals to me no end. Also I spent many years developing commercial systems on an AS400 built around a core product supplied by Caterpillar Systems (CAT). Their system provided many different "Hooks" onto which we hung our stuff and it all worked like a dream. So you can see why I'm keen on Drupal. So to the nitty gritty. I'm looking at nodes and have recently experimented with putting pure html into the node body.
This has worked fine. I have also used the nodeapi hook. In here I have put code that retrieves database records and formats the page by building tables with different styles and background colours and images etc. The code does all this when $op is Alter and so far it works fine. However I have a niggling feeling that this is probably not the right way to do it. Should I be approaching this in a different way perhaps using other hooks or am I on the right lines? I am aware of Views but from what little I have read I don't think I can do fancy formatting with it.

Cheers

Julie