The update of the QGIS documentation is managed by the Community Team Lead. Have a look at the QGIS Governance to find out who is in charge of guiding you.
The complete list of documents managed by the QGIS documentation team can be found at http://www.qgis.org/en/docs/index.html. A list of documenters can be found at https://github.com/qgis/QGIS-Documentation/graphs/contributors.
If you plan to contribute to QGIS documentation, see Becoming a documenter. For other related questions, please contact the Documentation Team Leader or subscribe with the qgis-community-team mailing list.
After subscribing to the mailing list you are able to send a mail directly to qgis-community-team@lists.osgeo.org asking for help.
We strongly encourage anyone dealing with documentation and its translations to join this list and promise that it is usually a very low traffic mailing list.
The other available mailing lists can be found at Mailing lists.
The QGIS project is always looking for people who are willing to invest some more time updating QGIS documentation and translating it into a foreign language - even perhaps to coordinate the update and translation effort.
We are trying to improve our project management process and spread the load more evenly between people who each have a specific area of responsibility, so any contribution you have to make will be greatly appreciated.
The complete list of documents managed by the QGIS Documentation Team can be found at http://www.qgis.org/en/docs/index.html. All the documentation sources are hosted in QGIS-Documentation repository. If you want to update some features in QGIS or document new ones, you need to:
Instructions for contributing in documentation and managing a git repository are available at Documentation Guidelines
Tip
Direct access to source file
To easily find the file to update in the repository, use the
Fix me link provided at the bottom of any page of the Testing
documentation. It directly opens the source file in your forked repo.
Just make your changes, commit in a new branch and submit pull request to the
main repository.