I've checked the videos and the FAQs, and I can't seem to find an answer to this simple(?) question:
How do you initially create a PhoneGap app within DreamWeaver?
The videos show things such as how to upload/build/install/etc such an app, but they all start with "here's the app that's ready to build". They already have assets such as "phonegap.js" as part of the project.