Best approach to OO Style (only slightly off topic)?

[Steve Simmons]

I'm relatively new to OO (and Python and QT ) and I am learning as I go 
along.  As I slowly come up to speed, I have some questions about the 
best approach to program/module structure so I'm looking for some 
pointers (URL's or replies).

I have copied some code from 'Rapid GUI Programming with Python and Qt' 
(Great book!) and am now modifying/extending it with my own.  The 
original code (Image Changer - Chp 6) is a single class that contains 
code for both UI creation/management and functional code. I have created 
a second class for my own code and I'm on the brink of adding calls from 
one class to the other and vice-versa.

At this point, I began to wonder what a 'correctly structured' OO 
program should look like. Should I separate GUI logic from 'business' 
logic?  Should everything be in one class?  Should my main() be carrying 
the high level logic?  Anyinput most welcome.

I looked briefly at the MVC model which answers my question at a high 
level but itrepresents another learning curve that I'm reluctant to add 
to my current challenge.

Steve