There are several ways to join the Hawkular community. The best option is always to talk to people and see what is going on. There are several ways to reach the developers and other community members.
Developer discussions happen on the hawkular-dev mailing list. To join the discussions please visit the list manager page at https://lists.jboss.org/mailman/listinfo/hawkular-dev and subscribe to the list.
Commit messages are sent to the hawkular-commits mailing list. You can subscribe at https://lists.jboss.org/mailman/listinfo/hawkular-commits
Hawkular issues and feature requests and ideas are captured in the Hawkular Jira instance at JBoss.org. There are several individual trackers for the various sub-project, but when in doubt, just use the Hawkular one and we will re-assign the submissions.
Similar to code, the Hawkular website and documentation lives under https://github.com/hawkular/hawkular.github.io. And as with the code, fork the repo, create your changes and open a pull-request.