newbie question: embedding Python into a C++ app and calling app functions

[davout]

I've a complete Python newbie so please forgive any dumb questions...

I'm looking to embed python as a scripting language into my C++ application.
The basic idea is to allow the app user to build custom scripts that join
toegther various process steps that are represented by process related
classes within my C++ app.

How can I define this so that my C++ process related classes are available
to a python script?