In general, it is a good idea to store the DITA files you create separately from DITA Open Toolkit, because:
A few simple entries in your Ant build scripts allow this separation.
Follow these steps to set up a directory environment and copy to it the garage and grocery shopping sample files that come with DITA Open Toolkit.
Your directory structure should look like this:
For information about setting up Ant scripts to find your DITA source files in this new directory structure, see Processing (building) and publishing DITA documents.
For information about creating demo files of your own, see Creating topics and Creating maps.