Mick, I think we need more information to answer your question. CRM has a defined schema out of the box that is setup to handle most Sales, Marketing, and Service scenarios. It's a platform that is designed to be totally customized to match your
business and processes, so there is no one 'right' or 'best' way to set it up.
Maybe refine your question a bit? The people here are very helpful, but will need some more specifics.
Thanks!