To use the InDesign SDK effectively, you must have the InDesign debug version installed. The InDesign debug can be accessed through the Adobe partner programs. You can sign up to one of the partner programs using the partner portal. Here's a link to the Solution Partner landing page. Here's a link to the Enterprise Developer Program page.
The Solution Partner program has been replaced by the Adobe Technology Partner program. Joining the Technology Partner program is by invitation only. You'll need an Adobe contact to recommmend you for the program. If you are not an enterprise developer and feel you should be eligable, you can send a private message to Harbs. I'm not an employee, but I'll be happy to pass your information on to someone who can help.