My project, GottenGeography, uses libchamplain in python, if you want to see a non-trivial example.
http://github.com/robru/gottengeography
Particularly the file gg/widgets.py shows what to import, how to start it, how to add it to your app.
Clutter is a little bit fussy with how you initialize it, so refer to gg/app.py to see the order of imports and how to initialize clutter.