The Orchard export file contain some contents that you can use to test your theme and site layout with. You can download the export file here.
These export files include a varied main menu and a foot menu, items of the most used content types and widgets and typography tests. You can log in with the credentials admin/password.
This page and many others here are part of the open source, portable package of Orchard goodies: the Orchard Dojo Library. The Library is freely accessible by anyone; just go to its repository to download its full content (you can even download the textual content of the Library as a big concatenated document in HTML), file issues or fork it! You can even edit it online on Bitbucket, just click on the Edit link in the upper right corner!