Contributing to the GNOME Documentation Project
Writing documentation can be a great way to build the free and open source community, discover how free software is created and meet the people who make it happen. There are different ways in which you can help, depending on your level of technical knowledge. Here are some different things to do to get started:
Join the team on IRC
The team generally hangs out on IRC, it's worth joining in!
Set up your testing environment
The Documentation Team only maintain documentation for the current release, so you need to be able to test the latest and greatest applications, which are very rarely provided by distributions.
Pick a project
You can start by either fixing issues in documentation, known as bugs. Some issues are already reported under the bug reporting system, Bugzilla at http://bugzilla.gnome.org or find your own bugs.
Pick an existing application
All documentation bugs are assigned to firstname.lastname@example.org
Either way, you'll want to do a git checkout of the application you're going to work on and submit a patch with your changes in GNOME Bugzilla.
Start using git
You will need to clone the git repository of the project that you want to work on and learn some git basics - the easiest way is to submit a patch using git. The GNOME git wiki page has everything that you will need to set up git and how to create a patch when you are ready. (Depending on the Linux distribution you use, you may have to install git).
Pro Git is a great resource, and explains everything that you are ever likely to come across.
Help is usually in the help/C/ repository inside the project.
Write in Mallard
Write, Write, Write
And edit, edit, edit. And spellcheck.
Do not be surprised if your first patch is sent back for review many times: this is quite normal and you should expect to have fewer reviews as you improve.
The best way to have your patches reviewed is to attach them on Bugzilla.
This may sound like a lot of stuff - but once you get set up a lot of it will come to you, and practice makes perfect. Most of us hang out in IRC, on irc.gnome.org in #docs, so you can usually get fairly quick answers (assuming you're on Europe or US time).