If you can't find help in the MariaDB documentation, in many cases the documentation for MySQL can be used. New features of MariaDB are mentioned on the MariaDB versus MySQL page and in greater detail under the MariaDB category.

If you have a question about a feature that is not properly documented or something that is not working as expected, go to the corresponding Knowledge Base page and ask your question there.

You can report and check on bugs which are unique to MariaDB in JIRA. MySQL bugs that also affect MariaDB should also be reported to MySQL.

You can also subscribe to the mailing lists and or join the IRC channel to communicate with MariaDB users and developers.

The MariaDB Corporation offers commercial support for MariaDB and all major MySQL versions (starting from MySQL 3.23).