JACK™ documentation is provided as part of the JACK™ Documentation package. This package is separate from JACK™ itself. Once installed, the documents (in PDF and HTML format) are in the doc subdirectory. You can access the JACK™ documentation from the Help menu of the JDE.

There should also be a link in the automatically installed menu or shortcuts. If not, point your browser at the file doc/jackdocs.html in the place where you installed JACK™ and it will guide you to all the available documentation.