Sierra Bullets has a nice manual and in it they discuss a lot of aspects of shooting and reloading.
See if you can find one and take a look at it.
Most of the other manuals either cover the very basics, like Brian said, or cover just different loads.
It may be that you are looking for other books by noted shooters (Elmer Kieth comes to mind) that delve in to the reasons and how they developed different loads.
Inside Every Bright Idea Is The 50% Probability Of A Disaster Waiting To Happen.