These are the sample files used by Comtech Services in their Introduction to DITA, by Jennifer Linton and Kylene Bruski.

HTML version

PDF version

Buy a copy of the book ($50 from Comtech), work through all their chapters, and do the exercises online here. You don't need to set up the DITA OT on your machine (a major hassle for some non-technical tech writers!).

In each member workspace folder there is a copy of the DITA source files for this example in the Comstar User Guide project.

You can edit the input source files in your browser using the Dita Storm editor and then generate (build) new multi-channel outputs with your changes.

To go to your DITA Manager, navigate to http://www.ditanews.com/Users/Guest/dita where you will find links to your source files, build files, action links to the build process, and output files.