As a free software project, phpMyAdmin is very open to your contributions. You don't need developer skills to help, there are several non-coding ways to get involved in a project (code is welcome too, of course!).
To gain practical experience in open-source development, you are welcome to contribute to phpMyAdmin. Usually, this is volunteer work, but since 2008, our project has been part of Google Summer of Code. This program "offers post-secondary student developers ages 18 and older stipends to write code for various open source software projects". So, join us soon and get ready for the next GSoC!
Interested in helping other users to use phpMyAdmin? You can join any of support we provide and help users there - IRC, mailing lists and web forums, where you can share your experience.
One of important things is to avoid problems in user interface. You can really help us here to provide feedback on releases and especially by testing pre-releases (alpha/beta/rc) we provide for testing. Just download them and report any issues you face with them.
Do you feel our documentation misses some points? We welcome additions, just let us know how you think the documentation can be improved. The best way is to submit a pull request against our GitHub repository. If you don't know how to make these changes, we still want to hear your input. You can submit a feature request explaining your suggested improvements.
Also documentation does not have to be text only, we would welcome to have some video tutorials giving users hints how to do specific tasks inside phpMyAdmin.
Coding contributions are very welcome, the easiest way is to fork our code on github and submit a pull request. We really welcome bug fixes or new features. You can find out more on developers page.
Our trackers, especially feature tracker contain dozens of entries which might already implemented or don't make much sense after years. You can go through reported issues, verify if they still apply to latest version and check whether they would be still useful. Also checking incoming reports for all required information or whether they were already not reported is welcome help.
We need money to allow our presence on conferences, buy new hardware or provide various useful services to our users and developers. By donating you help us in this area and possibly increase our presence on conferences.