This doesn't really apply to programming-related questions so much.
Because this will be such a specific site I feel we can be fairly confident that many of the 'troubleshooting' type questions will require the same information to deal with. That information would be the version of Magento, the version of PHP, what 3rd party modules do you have installed. The last bit there being an important one IMO.
Example (taken from a real experience): Setting a custom price for a product when creating an order through the backend fails.
Ultimately the issue was conflicts between the myriad of 3rd party modules that were installed. It didn't take me long to diagnose once I had the code, but had I known what modules were installed I would have been able to zero in on the culprit much quicker. Perhaps without having to fire up my debugger.
Off the top of my head, I would generally want to know:
- Magento Version
- PHP Version
- MySQL Version (sometimes)
- Apache Version (sometimes)
- Operating System (Simple as Linux/Windows/Mac in most cases)
- 3rd Party Modules Installed
- If you have custom modules (unlikely they can list exactly what they do in some cases. People love their IP)
- Does anything else not work on the site
As part of this, we could include educational material. Things like, how to find out what version of Magento you are running. And how to get a list of all your 3rd party modules. Make it as easy as possible.
Heck... What about making a module for connect that could produce a report that they can attach. Something to have all the version information but nothing personal (IP addresses, host names, etc).