There are several mechanisms in place to provide support to the ROS community, each with its own purpose: the wiki, ROS Answers, issue trackers, and the ros-users@ mailing list. It is important to pick the right resource to reduce response time, avoid message duplication, and promote the discussion of new ideas.
When something goes wrong, the wiki is your first stop. In addition to the official documentation for ROS packages, the wiki contains two key resources you should consult: the Troubleshooting guide and the FAQ. Solutions to many common problems are covered in these two pages.
If the wiki doesn't address your problem, ROS Answers is next. Take heart: it is very likely that someone else has faced the same problem before, and that it's covered among the more than 10,000 questions at ROS Answers. Start by searching for questions similar to yours; if your question isn't already asked, post a new one. Be sure to check the guidelines on how to prepare your question before posting.
When you've identified a bug (e.g., as a result of a discussion at ROS Answers), or when you want to request a new feature, head to the issue trackers. When reporting a bug, be sure to provide a detailed description of the problem, the environment in which it occurs, any detail that may help developers to reproduce the issue, and if possible, a debug backtrace.
To stay up-to-date on the latest developments within the ROS community, you'll want to subscribe to the ros-users@ mailing list. This list, which has thousands of members, is the place for announcements, news, and discussions of general interest. The ros-users@ list is not the right place to ask troubleshooting questions or report bugs; please use the other support resources instead.