Here are some links that you may find you refererence frequently while contributing to Python.
We encourage everyone to contribute to Python and that’s why we have put up this developer’s guide. You should read the following documents in the order provided. You can stop where you feel comfortable and begin contributing immediately without reading and understanding these documents all at once, but please do not skip around within the documentation as everything is written assuming preceding documentation has been read.
You can, however, read the FAQ at any point!
Anyone can checkout this guide from http://hg.python.org/devguide/. Core developers should use ssh://hg@hg.python.org/devguide instead, so that they can push back their edits to the server.
PEPs (Python Enhancement Proposals)