How do I report a bug?
On the Eclipse bugzilla log a bug to Eclipse > Platform > UI. You might want to read on what makes a great bug report.
Where can I ask a question?
You can ask questions on the Eclipse Platform newsgroup or the RCP newsgroup
How do I run the tests?
See "How to Contribute".
Where can I get the plugins?
For builds, go to the Eclipse download page. For source, see "How to Contribute".