Welcome to MR (MobileRead) Richard.
I've moved your thread to the calibre forum so members with more knowledge may help you get started.
First you may want to check out the top of this forum for the sticky threads of helpful information:
New to calibre? Start Here
and Video Tutorials
If you are familiar with calibre you may want to check out the calibre conversion forum
and the top of it for the sticky thread, Chapter Detection/Table of Contents Tutorial
I hope this is what you are looking for and that this gets you started.