As a new user, one of the most important things you can do to help Ubuntu improve is to file a bug report on Launchpad any time something doesn't behave like you expect -- it crashes, it behaves incorrectly or just doesn't do like it is supposed to do.

Filing bugs is easy and, in some cases, automated. To learn how to file a good bug report, and how to use Ubuntu's built-in bug filing system, take a look at the wiki page for bug reporting.

And thanks for helping out!