So you want to try out some Eclipse-RCP development on your own? There are several books out there about RCP. I strongly recommend the book: Eclipse Rich Client Platform : Designing, Coding, and Packaging Java(TM) Applications. At EclipseZone is a good review.
While you wait for the book to be shipped, get the sample chapter to learn something about the concepts of Eclipse RCP. Afterwards build your own first RCP-Application with the "New Plugin-Porject"-Wizard of Eclipse: File | New | Project | Plugin-Project. At the Wizard-Page "Plug-in Content" select that you want to create a rich client application. If you select "RCP Mail Template" you will get a nice starter project to fool around with RCP. The created mail example looks like this: